Parasitology Written Midterm

defining characteristic of Ancylostomatoidea

1. Bent head 2. Oral cutting plates or teeth

What are two features of Heterakis gallinarum that distinguish it from other poultry Ascarids?

1. H. gallinarum worms are somewhat smaller than other Ascarids (~1 cm) 2. Birds can tolerate relatively heavy infections (some nodule formation, some intestinal wall thickening, and inflammation; decreased egg production)

symptoms of LARVAL CYATHOSTOMOSIS

1. Hemorrhagic enteritis 2. Rapid weight loss 3. Mild recurrent colic 4. Peripheral edema 5. Sudden onset diarrhea when larvae emerge into lumen

Pathogenesis of Stephanurus dentatus L4:

1. Severe cirrhosis 2. Liver failure 3. death

stages of hookworm disease

1. Skin Penetration Phase 2. Respiratory Phase 3. Intestinal Phase

The first stage larva of a cestode, infective for first (or only) intermediate host. Consists of an embryo (hexacanth - 6 hooks) surrounded by two embryonic membranes

oncosphere

Hookworms transmitted by the transmammary route are particularly pernicious because _____

patency occurs seven days earlier than it normally would

Seasonality (eggs/g greater in summer than winter months) is typical of ___ and __ hookworm transmission

percutaneous and oral

Many types of infectious nemotodes have a ______ that keep them viable in the environement for extended amounts of time

protective covering

Dirofilaria immitis are parasites of the ____________(location) of ____________(species).

pulmonary arteries and right ventricle; dogs, cats, ferrets

transmission of Ancylostoma caninum is greatly linked to the ___ cycle, since the parasites seem to sense ____ hormones to facilitate their transmission

reproductive, reproductive

A reduction in the _____ of the dam permits greater establishment and fecundity of the worms.

resistance

Nanophyetus salmincola is a zoonotic intestinal fluke in the family Troglotrematidae. This family infects definitive hosts through consumption of a secondary intermediate hosts. What is N. salmincola's secondary intermediate host?

salmonids

Digenea have complex lifecycles with distinct developmental stages and intermediate hosts. They have alternating __________ (definitive host) and ___________ (intermediate host) reproduction

sexual; asexual

TRICHOSTRONGYLES pathogenesis is ____ related

site

What is the predilection site of Ascaris suum?

small intestine

Trichostrongylus colubriformis infects the ____ and causes mucsal disruption, distortion and flattening of villi, and protein and protracted diarrhea

small intestine (ruminants)

Adult cestodes (tapeworms) reside in the ________ of definitive hosts, with eggs and gravid segments found in or near host feces. Definitive hosts become infected by ingesting infected secondary hosts harboring _____________ cestodes.

small intestine; larval

Acanthocephalans are known as the _____________ worms

thorny or spiny headed worms

what is the pre-patent period?

time before you can detect the infection, but animal is still infected

It is rare to see an adult Dioctophyma renale worm infection in the left kidney (T/F).

true (Most Dioctophyma renale infections are unilateral and involve only the right kidney.)

T/F- Small strongyles are less pathogenic than large

true- because buccal capsule is quite small, but can cause more pathology in the host due to sheer numbers

In heavy infections of Oesophagostomum spp, a chronic _____ forms associated with inappetence and emaciation

ulcerative colitis

what is the patent period?

when you can diagnose the patient and conclude the animal is infected

when do ostertagia arrest in the NE? in the south?

winter, summer

At the end of the Toxocara canis life cycle (an Ascarid), eggs are shed into the environment from feces. Approximately how long does it take for the eggs in the environment to become infectious? What stage of development must the egg be in in order for it to be infectious?

~2 weeks. Eggs must develop L2 larvae to be infectious.

worms in TRICHOSTRONGYLIDAE family

HOT 1. Haemonchus 2. Ostertagia 3. Trichostrongylus

state of inhibition of larval development that is a survival mechanism that allows resumed development and disease

HYPOBIOSIS (ARRESTED DEVELOPMENT)

Dog schistosomes. Eggs evoke granulomatous response. Usually asymptomatic, but can cause lethargy, slow, chronic weight-loss, diarrhea. In extreme cases, can be fatal.

Heterobilharzia americana

____________ tapeworms are found in extraintestinal tissues in intermediate (and sometimes definitive) hosts and can cause severe pathogenesis. With a few exceptions, ____________ tapeworms are not particularly pathogenic

Larval; adult

Dirofilaria immitis life cycle. Mosquito will ingest _______ during blood meal

Microfilariae

The majority of Ascaris suum pathogenesis is caused by what?

Larval migration (through liver, lungs, and small instestine)

Parasites of the stomach of carnivores. Pinkish and tend to live with the anterior end embedded in the mucosa. In dogs, it may be found in the very anterior most portion of duodenum

Physaloptera sp.

Eggs that are slightly flattened on one side, curved on the other, and have a plug at one end (operculum) are characteristic of what type of worms?

Pinworms (Order Oxyurida)

What is unique about male and female adult schistosomes?

They are paired. The female is like inside the male its freaking weird. *they're also very long lived! decades in humans

(T/F) Dirofilaria immitis is capable of abnormal migration

True but uncommon! *Seen in eyes, CNS, skin, peritoneal cavity, and peripheral vasculature.

(T/F) The cercariae of schistosomes are directly infective.

True!

Describe the eggs of Spirocerca lupi

Very small. Eggs are narrow, ellipsoidal, and cylindrical. Have a smooth shell wall with a fully developed LARVA COILED INSIDE

Dicrocoelium dendriticum are liver flukes in the family Diplostomatidae. This family infects definitive hosts through consumption of a secondary intermediate hosts. What is D. dendriticum's secondary intermediate host?

ants! *they have a terrestrial life cycle!!!

DH's of nematodes are infested with ___ stages of parasitic nematodes

adult

Trichostrongyles: One egg = one ____

adult

A. caninum host susceptibility declines with advancing ____. why?

age 1. Physiological resistance 2. Acquired immunity

Trichostrongyles: Host resistance is a function of __ and ___

age, development

Metacercariae of platynosomum fastosum a fluke of the bile and pancreatic ducts of cats are found in _____________ (species) giving it's disease the name _______________

amphibians, lizards, geckos; lizard poisoning *it has a terrestrial life cycle

Characteristics of Cyclophyllidae one of the main orders of cestodes. 3) Have ___________ lateral for fertilization 4) Segments have _______ openings for eggs to escape. Eggs accumulate until segment is packed

genital pore; no

ostertagia are found in the ___ of the abomasum

glands

Thelazia sp. are parasites of the ____________(location) of domestic and wild animals. They are known as "_________"

conjunctival and lachrymal sacs; EYE WORMS

Trichostrongyles: Arrested development allow parasites to respond to changes in the ____

environment

Trichostrongyles have specialized worm ____ that can inform how they cause disease

heads

Paragonimus kellicotti is known as the North American _________ fluke. It is in the family Troglotrematidae (infect definitive hosts through consumption of secondary intermediate hosts).

lung *eggs can be visualized on fecal float

Ascarids eat blood and tissue of hosts, making them plug feeders. This means they have a buccal capsule (T/F).

false (Ascarids are NON-plug feeders and DO NOT contain a buccal capsule. They eat digested or partially digested food in the lumen of the gut.)

What is one concern after treatment of heavy Parascaris equorum infections in foals?

impaction

The Dioctophyma renale life cycle is (direct/indirect).

indirect

There are 3 infection routes of Toxocara canis (+ T. catis): direct, indirect (paratenic), and vertical transmission. Infections of the __________ route are light when acquired in this manner due to the robust host immune response.

indirect (paratenic)

Male Ascarids use copulatory bursa to facilitate copulation with females (T/F).

false (Ascarids are non-bursate nematodes--no copulatory bursa!)

Oxyuris equi eggs are directly shed into the environment from horse feces (T/F).

false (Eggs are shed onto the perianal skin and eventually are shed into the environment)

Heterakis gallinarum is an Ascarid that infects the colon of pheasants, turkeys, chickens, and other fowl but is most severe in young turkeys, where mortality can reach up to 100% (T/F).

false (H. gallinarum by itself is not severely pathogenic--birds can tolerate relatively heavy infections--but it acts as a transport host for another parasite, Histomonas meleagridas, which IS most severe in young turkeys and can cause up to 100% mortality)

Ascarids that infect poultry such as Ascaridia galli and Heterakis gallinarum progress through their life cycle via migration through the liver, lungs, and then to the GI tract (T/F).

false (NO migration in chicken tissues)

The PPP (pre-patent period) for Ascaris suum is shorter in the indirect (paratenic) life cycle as opposed to the direct life cycle because it bypasses tracheal migration (T/F).

false (PPP is the same for both because both require tracheal migration)

Ascarids in the parasitic phase are non-migratory. They stay in the small intestine (T/F).

false (Parasitic phase includes migration through tissue)

There are many pinworms that are host-specific to many species that can cause severe pathogenesis (T/F).

false (Pinworms are generally not pathogenic)

where does dictyocaulus viviparus migrate to in the body?

lungs

All 8 Trichinella species are only found in mammals (T/F).

false (Some species infect birds, mammals, and/or reptiles. Ex: T. pseudospiralis = birds and mammals; T. zimbabwensis = crocodiles)

Earthworms and dung beetles can act as paratenic hosts for Parascaris equorum (T/F).

false (There are NO known paratenic hosts for P. equorum. Earthworms and dung beetles are paratenic hosts for Ascaris suum, a swine Ascarid.)

Fecal egg count (FEC) reflects the number of worms in the small intestine (T/F).

false (There is no relationship between FECs and the number of worms in the small intestine, although very high FECs are often associated with high worm burdens. There is an ultrasound scoring system that reliably can identify high worm numbers)

Trichuris and Eucoelus can be found in mammals, birds, and reptiles (T/F).

false (Trichuris and Eucoelus is ONLY found in mammals. Some species of Trichinella can infect mammals, birds, and reptiles.)

If a pig is being actively treated for Trichuris infection, it is not necessary to move the pig to another pen because the pig's feces will no longer contain eggs after treatment (T/F).

false (Trichuris eggs are very resistant. If a host is in contact with or living in a contaminated environment, treatment is not enough. Reinfection is very common for Trichuris due to environmental durability.)

Metastrongylus sp. are lungworms, so the best diagnostic test is Baermann (T/F).

false (Use fecal floatation for detection of larvated eggs)

The best diagnostic for all lungworms is the Baermann technique, which detects migrating larvae in the stool. It is useless to perform fecal floats on lungworms because there are no adults shedding eggs in the GI tract (T/F).

false! (Not all lungworms can be detected by Baermann. Some parasites that cause respiratory disease can be detected by fecal float. Why it's important to know the life cycle of each species! If you're unsure of the species, ask for both tests.)

T/F- Diagnosis of Oesophagostomum spp. is easiest in young animals

false- Difficult in young animals because diarrhea may happen in the pre-patent period with no eggs in feces

T/F- drugs are equally as effective to parasites in the hypobiosis state as in normal development

false- hypobiosis is refractory to some drugs

Order Strongylida eggs are passed in the ____

feces

noninfectious animal disease are caused by ____

genetic defects, physiological abnormality, structural dysfunction, external factors

treatment for Stephanurus dentatus infection

ivermectin and Fenbendazole

Fasciola hepatica is a liver fluke capable of causing both acute and chronic disease. Acute disease is a result of direct damage to the liver caused by the migration of __________ and secondary ___________ infection. Chronic disease is associated with the presence of __________ trematodes feeding on blood leading to anemia, and living in the bile duct leading to bile duct hyperplasia, fibrosis, and calcification.

juveniles (maritas); Clostridium; adult

What is the predilection site of Dioctophyma renale?

kidney (Giant Kidney Worm)

predilection site of OESOPHAGOSTOMUM

large intestine

Human echinococcosis (hydatid disease) is caused by the __________ stages of cestodes of the genus Echinococcus

larval

Severity of Fasciola hepatica (liver fluke) pathology is associated with _________

levels of infectious dose *Acute type 1 (highest) → acute type II → subacute fasciolosis → chronic fasciolosis

What is the main method of control and prevention of physaloptera sp.?

limit access to intermediate and paratenic host

Dicrocoelium dendriticum is a ___________ fluke in the family Dicrocoeliidae (infect definitive hosts through consumption of secondary intermediate hosts)

liver fluke! *also known as lancet fluke or "brainworm"

Describe the generalized life cycle of cestodes

1) Adults in the GI tract released eggs in teh feces 2) Eggs ingested by intermediate host hatch in gut and metacestode develops 3) Either ingested by definitive host, second intermediate host (2nd metacestode develops), or paratenic host

Dracunculus sp. life cycle. (Direct/indirect) life cycle. Intermediate host (IH)/vector: _______ Paratenic hosts (PH): __________ Definitive host (DH): ___________

1) INDIRECT 2) copepods 3) frogs/fish 4) dogs (recent reports in cats)

Spirocerca lupi have an ___________ life cycle requiring a __________ intermediate host containing infective L3s. Rodents, chickens, birds, reptiles can act as paratenic hosts

1) INDIRECT 2) coprophagous beetles

Habronema sp. and Draschia sp. have a ___________ life cycle. Hosts get infected when they ingest the intermediate host ___________ which contain infective L3s.

1) INDIRECT 2) flies (musca domestic, stomoxys calcitrans) *L1 ingested by maggots molt and migrate to fly head. L3 change hosts when fly lands on animal. Swallowed by animal and complete life cycle.

What are the two important orders of cestodes to veterinarians?

1) Cyclophyllidae 2) Pseudophyllidea

What treatment and control is available for Fasciola hepatica (liver fluke)

1) Drugs - most against adults only 2) Mulluscicides, draining ponds 3) Move to fluke free pastures

What is the order of digenea maturation?

1) Egg 2) Micarcidium 3) Sporocyst 4) Cercaria 5) Metacercaria 6) Adult

Describe the typical life cycle of acanthocephalans

1) Eggs are shed in feces 2) Eggs ingested by beetle intermediate host and grow from acanthor to cystacanth stage 3) Definitive host becomes infected by ingestion of infected beetles 4) cystacanth excysts in host small intestine - adult in small intestine

What two families of digenean parasites are most likely to infect definitive hosts by being ingesting metacercariae encysted on vegetation?

1) Fasciolidae 2) Paramphistomatidae

Onchocerca lupi have a ___________ life cycle. In a nodule in the host's eye, adult worms produce microfilariae, which migrate to the skin. When the parasites' vector (___________) take a blood meal, they ingest MF. In the vector, the MF develop to L3, migrates to mouth parts and transmit to the next definitive host, such as humans and animals, during blood meal.

1) INDIRECT 2) blackflies and/or biting midges

Thelazia sp have a ___________ life cycle. The worms are ___________ so the L1 is passed by the female worm into the lacrimal secretion which is then ingested by the intermediate host _________. Development from L1 to L3 develops in the intermediate host which then transfers infectious L3s to the definitive host when it feeds

1) INDIRECT 2) viviparous 3) drosophilid flies

Physaloptera sp. life cycle. 1) (Direct/indirect) life cycle. 2) Infective stage: IH containing L3 3) Intermediate host (IH): ____________ 4) Paratenic host (PH): ____________

1) INDIRECT 3) Coprophagous beetles, crickets; 4) cold blooded vertebrates

Treatment of Habronema sp. and Draschia sp. infection includes: 1) ___________ and ___________ as the treatments of choice for ________ Habronema and Draschia species. 2) _________ is approved for the treatment of SUMMER SORES

1) IVERMECTIN and MOXIDECTIN; ADULT 2) IVERMECTIN

Describe Alaria spp transmission cycle.

1) In DH adult worms in the gut pass eggs in the feces 2) Snail intermediate host - asexual reproduction 3) Mesocercariae in tadpoles 4) Tadpoles eaten by paratenic or definitive host 5) In DH, mesocercariae migrate to lungs and form metacercariae 6) They either travel to the gut and become adults or metacercariae form in mammary glands instead of lungs and vertical transmission occurs

Describe the generalized digenean (trematode) life cycle.

1) In the definitive host adult worms reproduce sexually 2) Eggs released in feces, sputum, mucus, and urine 3) Eggs enter fresh water and hatch (miracidium) 4) Asexual reproduction occurs in the SNAIL intermediate host (sporocyst) 5) Potential second intermediate host (cercaria -> metacercaria) 6) Definitive host (adult) becomes infected

Classic clinical signs of spirocerca lupi infection?

1) Infections are often SUBCLINICAL. 2) CYSTIC NODULES - fistulas. *Dysphagia, vomiting, esophageal Neoplasia, aortic aneurism or rupture, secondary pulmonary Osteoarthropathy

What are some other differential diagnosis for spirocerca lipi?

1) Larvated hookworm eggs (old feces) 2) Physaloptera sp: physaloptera eggs are larger and less elongated than Spirocerca eggs.

Severity of heartworm disease depends mainly on which three factors?

1) Number of Adult Worms 2) Duration of Infection 3) Individual Host Response

Species of onchocerca sp. that are ZOONOTIC!

1) Onchocerca lupi - found in the eyes (external parts of the ocular apparatus)

The environment affects the timing of disease and treatment for Fasciola hepatica (liver fluke) infection. How do these factors differ in the Pacific Northwest vs the Southern US?

1) Pacific Northwest - transmission in late summer, acute disease in autumn, adults in winter 2) South East - transmission in winter due to summer drought, acute disease in spring, adults in summer

Describe Dipylidium caninum's life cycle

1) Proglottids containing eggs are shed in feces 2) Flea larvae eat eggs 3) Flea matures 4) Dog (or human) ingests flea 5) Parasite larvae migrate to small intestine where they mature

What is the appropriate control and prevention for dracunculus sp?

1) SAFE WATER! 2) Vector control (Copepods) 3) Health EDUCATION and community mobilization

Species of thelazia sp that are ZOONOTIC!

1) T. californiensis (endemic in West US) 2) T. callipaeda

Differential diagnosis of adult worm found in conjunctival sac

1) Thelazia sp. 2) Onchocerca sp.

What three families of digenean parasites are most likely to infect definitive hosts when they consume infected fish, amphibians, crayfish, crabs, etc?

1) Troglotrematidae (N. salmincola, P. kellicotti) 2) Diplostomatidae (Alaria) 3) Dicrocoeliidae (P. fastosum, D. dendriticum)

Characteristics of Pseudophyllidea one of the main orders of cestodes. 1) • Scolex has two shallow longitudinal grooves (__________) that are used for attachment and locomotion 2) Segments have __________ for release of eggs. Segments discharge eggs until supply is exhausted and the terminal segments become senile rather than gravid 3) Require ___________ intermediate hosts

1) bothria 2) uterine pore 3) at least two

Treatment of gyrodactylus spp (monogenea) include:

1) copper sulfate baths 2) formalin 3) hydrogen peroxide 4) praziquantel

What are the three ways a definitive host can get infected by a digenean parasite?

1) eat metacercariae encysted on vegetation 2) eat infected secondary intermediate host 3) direct penetration of the skin by larval cercariae

Describe the life cycle of a cestode in the family Taeniidae

1) eggs in feces pass into the environment 2) intermediate host becomes infected by ingesting eggs/gravid proglottids 3) eggs hatch and enter musculature where they develop cysticeri in muscle 4) humans are infected by consuming raw/undercooked meat 5) adult forms in small intestine

What are some of the factors contributing to the spread of dirofilaria immitis?

1) environmental and climatic changes 2) relocation of infected dogs 3) expansion of infected wild canids

Some signs that help you make suspect Dirofilaria immitis infection include

1) history 2) lack of preventative 3) exercise intolerance

Dirofilaria immitis life cycle. 1) (Direct/indirect) life cycle. 2) Definitive hosts: _________ 3) Intermediate host: ____________

1) indirect 2) DOGS! - wild canids, cats, wild felids, ferrets, marine mammals, humans 3) mosquitoes (culicidae)

Clinical signs and pathogenesis of onchocerca lupi

1) initial stage - nonspecific (lacrimation, photophobia, conjunctivitis) 2) chronic stage - typical nodules

Dracunculus sp. have an INDIRECT life cycle requiring an intermediate/vector (copepod) or paratenic (frog/fish) host containing L3. They have a ________ prepaitent period with worms taking __________ to mature. Females form a blister in the skin to deposit the next generation of larvae

1) long 2) 1 year

The American Heartworm Society recommends annual testing for heartworm using: 1) Antigen Test: ELISA kits which detect ___________ 2) Microfilariae testing: _____________ and smear

1) mature adult female Ag 2) modified Knotts *additional tests include radiography, echocardiography

Alaria spp are intestinal flukes in the family Diplostomatidae. They are particularly unique as their lifecycle has which two unusual characteristics?

1) mesocercaria stage 2) vertical transmission via milk ducts to sucklings

Attachment of acanthocephalans such as macracanthorhynchus hirudinaceus to the intestine leads to ____________

1) necrosis at local site 2) flattened villi

Pathogenesis of macracanthorhynchus hirudinaceus. Ulceration and granuloma formation at site of infection with two phases. 1) Acute: marked by ____________ as a result of mechanical disruption of the instine wall 2) Chronic: related to ______________. Results in diarrhea, wasting and failure to thrive.

1) peritonitis 2) worm burden - competition for nutrients *can also be asymptomatic

How do you diagnose acanthocephalans such as macracanthorhynchus hirudinaceus infection?

1) presence of eggs (thick brown shell, acanthor) 2) ID adults

How do you handle management and control of acanthocephalans?

1) remove contact with intermediate host 2) drug treatment (levamisole, ivermectin) that prevents worms from attaching

At what stages do digenea (trematode) undergo sexual and asexual reproduction?

1) sexual: definitive host 2) asexual: intermediate host - snail

Environmental cues affect Fasciola hepatica (liver fluke) in multiple ways. 1) Development of miracidium (9 days) is dependent on _______and _________. 2) Larval development (6-7 weeks) in snail is delayed by low ___________. 3) Metacercariae survive on pasture for approx 3 months and are resistant to ____________ and ___________.

1) temperature and moisture 2) temperatures 3) freezing and drying

Diagnosis of Trichuris sp. and Capillarids (Eucoleus, Pearsonema): 1. ______________ is the BEST option for recovering parasites from feces during a fecal float. 2. ____________ is the BEST fecal float solution to use for Trichuris and Eucoleus. 3. A ________ floatation is used to diagnose Pearsonema plica.

1. (Double) centrifugal floatation (best option, as opposed to passive floatation) 2. Sugar (Sheather's sugar solution--as opposed to salt [large animals] and zinc [Giardia]) 3. Urine (NO P. plica should be in feces! If you find it, resubmit your sample coz it's contaminated!)

1. Approximately how long does it take for an Ascaris suum egg newly shed into the environment to become infectious? 2. What factor is this timeframe dependent on? 3. What stage of larval development is necessary for the egg to be infectious?

1. 3-6 weeks 2. temperature 3. L2

Describe the life cycle of Toxocara canis (+ T. catis--same cycle) through vertical transmission via the transmammary route.

1. A mature dog (< 6 mo) ingests eggs containing L2 larvae (infectious stage of egg). 2. L2s hatch and migrate to the liver, followed by the lungs. 3. L2s undergo somatic migration (bc mature dog): L2s disseminate to tissues and encyst (hypobiosis). 4. Encysted hypobiotic larvae become activated and migrate to the mammary glands. 5. L3s are ingested by nursing pups 6. L3s molt to L4s in the stomach 7. L4s molt to adults in the small intestine of pups

Describe the life cycle of Toxocara canis through vertical transmission via the transplacental route.

1. A mature dog (< 6 mo) ingests eggs containing L2 larvae (infectious stage of egg). 2. L2s hatch and migrate to the liver, followed by the lungs. 3. L2s undergo somatic migration (bc mature dog): L2s disseminate to tissues and encyst (hypobiosis). 4. In female dogs that become pregnant, L2s become activated--at 41-45d into pregnancy, arrested larvae respond to hormone levels (have prolactin receptors similar to that of dogs) 5. Activated L2 larvae undergo transplacental migration to the fetal liver, where they again become hypobiotic. 6. When the pup is born, L2s reactivate and migrate from the liver to the lungs. 7. L2s undergo tracheal migration (bc young pup): L2s molt to L3s and pass up the bronchial tree 8. L3s are swallowed in the pharynx 9. L3s molt to L4s in the stomach 10. L4s molt to adults in the small intestine, where they mate and produce eggs that are passed in the feces.

Describe the life cycle of Toxocara canis (+ T. catis--same cycle) through a paratenic host (indirect life cycle).

1. A paratenic host, such as a rodent or bird, ingests an egg containing L2 larvae (infectious stage of the egg) 2. L2 hatches and migrates to the liver and then to the lungs. 3. From the lungs, L2 undergoes somatic migration: L2s enter systemic circulation and disseminate and encyst into tissues. 4. L2s become hypobiotic and are maintained in the paratenic host tissues. 5. Dog eats paratenic host, and L2s become activated. 6. L2s molt to L3s and then to L4s. L4s return to the small intestine, where they molt into adults.

Describe how Heterakis gallinarum acts as a transport host for the protozoan parasite Histomonas meleagridis.

1. Adult worms of Heterakis gallinarum, as well as Histomonas meleagridis, reside in the cecum. 2. Histomonas meleagridis infects Heterakis gallinarum through its genital openings, infecting its eggs. 3. When Heterakis gallinarum sheds its eggs, both Heterakis gallinarum and Histomonas meleagridis are shed together. 4. Eggs can be viable in the soil for 2 years!

Occasionally, heavy Trichuris infections can cause severe disease. Describe clinical signs of severe disease typically seen in each animal: 1. Dogs 2. Ruminants 3. Pigs

1. Alternating periods of bloody, mucoid diarrhea with periods of normal stool. Anemia 2. Young animals may suffer massive (sometimes fatal) hemorrhage in the lumen of the cecum (rare, more likely in animals with specific habits or previous hemorrhagic intestinal disease) 3. Young animals may have catarrhal enteritis (diarrhea, dehydration, anorexia, and retardation of growth). May also be associated with bacterial infections (C. jejuni).

Clinical signs of HAEMONCHOSIS

1. BLOOD LOSS Anemia -Palor -Weakness -Dyspnea 2. Hypoproteinemia -Edema-Weight loss

1. What technique is used to diagnose Aelurostrongylus abstrusus? 2. What morphological characteristics allow us to identify A. abstruses?

1. Baermann test (most reliable) for detection of L1 in feces 2. L1 larvae have a severe kink (S-shaped curve) at the tail end and a dorsal accessory spine.

1. What technique is used to diagnose Crenosoma vulpis? 2. What morphological features help distinguish Crenosoma?

1. Baermann test for detection of L1 in feces 2. L1s tend to assume a C shape when killed. They have NO kink (S-shaped curve) nor a dorsal spine.

1. What technique is used to diagnose Strongyloides spp.? 2. At what stage of development is Strongyloides spp. easiest to identify? Why? 3. What technique can be used to ensure the larvae are at this stage?

1. Baermann test for detection of L1 in feces 2. L3 because they have a distinctively long esophagus 3. Coproculture (fecal culture) lets the larvae continue to molt from L1 to L3

1. What technique is used to diagnose Angiostrongylus vasorum? 2. A. vasorum appears very similarly to A. abstrusus--they both have an S-shaped curve and accessory dorsal spines. What is the key morphological difference seen in A. vasorum? 3. How does the geographic prevalence of A. vasorum influence our diagnosis?

1. Baermann test for detection of L1 in feces (Other tests: radiographs, antigen tests, qPCR of bronchoalveolar lavage samples) 2. A. vasorum has a cephalic button on its anterior end 3. A. vasorum is uncommon in North America! (If it looks like A. abstrusus, it probably is.)

1. What method is used to diagnose Protostrongylus rufescens and Muellerius capillaris? 2. Why must this method be used? 3. Once isolated, how are the two species distinguished from one another? 4. What other species must you consider, and why?

1. Baermann test for the detection of L1 in feces. 2. Adult worms release larvae into the feces, NOT eggs. Fecal float cannot be used. 3. By morphology: M. capillaris has a kinked tail with an accessory spine, whereas P. rufescens has a plain tail. 4. Dictyocaulus spp. because it is another L1 that is found in the feces of small ruminants.

what are Trichostrongyles strategies for reproductive success?

1. Biotic potential - how many eggs are produced. 2. Motile intermediates - allow dispersal 3. Overwintering larvae 4. Arrested development allows parasites to respond to changes in the environment 5. Periparturient Rise - exposes naïve newborns to parasites 6. DRUG RESISTANCE

Cuticular features of nematodes

1. Buccal capsule (mouth area for feeding) 2. Alae - Cuticular evaginations ("wings")

1. Who are the definitive hosts for Aelurostrongylus abstrusus? 2. What is the predilection site?

1. Cats and (rarely) dogs 2. Terminal respiratory bronchioles and alveolar ducts (LUNGWORM)

1. What technique is used to diagnose Filaroides sp.? 2. What sample is used for this technique? 3. What morphological characteristics are present in Filaroides sp.?

1. Centrifugal zinc floatation for the detection of L1 in feces (Baermann NOT recommended bc larvae passed in feces are usually dead) 2. Bronchoalveolar lavage sample 3. Have severe kink (S-shaped curve) but LACKS a dorsal spine

How is Ascaris suum diagnosed?

1. Clinical signs: respiratory → transient cough in young pigs 2. Characteristic eggs in feces (thick-walled, ovoid eggs with rough surface--"sticky") 3. Necropsy: milk spots in liver, pneumonia, and adults in small intestine

Blackhead disease has broken out in one of your turkey flocks. What do you do?

1. Cull sick animals (no drugs to treat Histomonas meleagridis infection) 2. Treat flock with preventative worming for Heterakis gallinarum, the transport host for Histomonas.

who are the Small Strongyles?

1. Cyathostomum 2. Cylicocyclus 3. Cylicostephanus 4. Cylicodontophorus

Chronic Strongyloides spp. is unique to humans. 1. What is the cause of this chronicity? 2. What are the two ways chronicity is perpetuated?

1. Development of L3 larvae within the digestive tract, followed by autoinfection, in which a human can be reinfected without contact with the infective stage in the environment. 2. Internal autoinfection: L3 reinvades the host by penetrating the bowel walls. External autoinfection: L3 reinvades the host by penetrating the perianal skin.

1. The life cycle of Filaroides sp. is (direct/indirect). 2. The infective stage is considered to be the _____ larvae. 3. All 5 stages of larval development occur in host _________ tissues. 4. Eggs hatch into L1 larvae (before/after) exit through the __________ or ________. 5. L1 larvae reach infectivity _________ after exiting the definitive host.

1. Direct 2. L1 3. Lung 4. Before, feces, saliva 5. IMMEDIATELY

1. The life cycle of Strongyloides spp. is (direct/indirect). 2. The primary route of transmission is ____________ by L3 larvae, although some species can undergo ___________ transmission. 3. The PPP (pre-patent period) is _________. 4. Adult females lay eggs in the ___________. 5. Once hatched, L1 larvae can take one of two life cycles: 6. The ____________ occurs only in the definitive host, and there is NO free-living adult stage in the environment. L3 larvae become ______________ females, meaning they can reproduce asexually. 7. The ____________ is when both adult stages (male and female) and free-living stages occur in the environment.

1. Direct 2. Skin penetration, transmammary transmission 3. Short (1 week) 4. Small intestine 6. Homogonic cycle, parthenogenetic 7. Heterogonic cycle

1. The life cycle of Crenosoma vulpis is (direct/indirect). 2. The intermediate hosts are ________. 3. The infective stage is considered to be the intermediate host containing ____ larvae. 4. ____ larvae ascend the trachea and are released from the feces of the definitive host. 5. The PPP (pre-patent period) is ________.

1. Direct 2. Snails 3. L3 4. L1 5. Short (19 days)

What are the two modes of transmission of Ascaris suum in pigs?

1. Direct transmission: pig consumes infective egg containing L2 larvae 2. Indirect transmission: pig consumes paratenic host (earthworm or beetle) infected with A. suum

1. Who are the definitive hosts of Crenosoma vulpis? 2. What is the predilection site? 3. Where does Crenosoma get its name from?

1. Dogs (+ foxes, wolves, raccoons, and other canids) 2. Bronchioles, bronchi, and trachea 3. Characteristic cuticle on adults with crenated folds

1. Who are the definitive hosts of Angiostrongylus vasorum? 2. What is the predilection site?

1. Dogs, coyotes, foxes 2. Pulmonary arteries and lungs

1. Who are the definitive hosts of Strongyloides spp.? 2. What is the predilection site? 3. What is the common term for Strongyloides spp.?

1. Domestic animals and humans (ZOONOTIC) 2. Small intestine 3. Intestinal threadworms

Name the place where each larval stage of development of Toxocara canis occurs: 1. L1 to L2 2. L2 to L3 3. L3 to L4 4. L4 to adult

1. Egg in environment (yields infectious form of egg) 2. Lungs for tracheal migration, encysted tissues for somatic migration (dog) 3. Stomach (dog) 4. Small intestine (dog)

Describe the life cycle of Dioctophyma renale. Include the PPP (pre-patent period) and why it's so darn long.

1. Eggs are ingested by the intermediate host (annelid). 2. Definitive host ingests the intermediate host OR ingests a paratenic host (fish or frog). 3. The larvae penetrate the intestinal wall, enter the peritoneal cavity, and finally the kidney. 4. The PPP = 6 months. The unique route of this worm is what makes it so long.

Describe the life cycle of Parascaris equorum.

1. Eggs are shed into the environment. Between 10d and 6w, eggs develop into L2 larvae (infectious stage; can survive in the soil for 5-10y) 2. Direct life cycle ONLY (no known paratenic hosts): foal ingests infective egg. 3. Larvae hatch and migrate to the liver and then the lungs where they undergo tracheal migration: migrate to trachea, cough up, and swallow. 4. Larvae return to small intestine, where they mature into egg-laying adults.

Describe the general life cycle of an Ascarid, such as Toxocara canis, when consumed by a dog. Continue the cycle if the larvae were to undergo tracheal migration.

1. Embryonated egg is ingested by the host 2. L2 hatches and penetrates the wall of the small intestine. 3. L2 migrates to the liver via portal circulation. 4. L2 migrates to the heart and then to the lungs. 5. L2 undergoes tracheal migration: L2s break out of capillaries into alveoli, molt into L3s, and migrate up the bronchial tree 6. L3s are swallowed in the pharynx 7. L3s molt to L4s in the stomach 8. L4s molt to adults in the small intestine, where they mate and produce eggs that are passed in the feces.

Describe the general life cycle of an Ascarid, such as Toxocara canis, when consumed by a dog. Continue the cycle if the larvae were to undergo somatic migration.

1. Embryonated egg is ingested by the host 2. L2 hatches and penetrates the wall of the small intestine. 3. L2 migrates to the liver via portal circulation. 4. L2 migrates to the heart and then to the lungs. 5. L2s migrate through the lungs and return to the heart (do not get coughed up) where they enter systemic circulation. 6. L2s disseminate and encyst in tissues and become hypobiotic until the host is either eaten by another host (if in paratenic host) or until it can become vertically transmitted (ie pregnancy/lactation)

The severity of disease from Trichinella sp. infections in humans is dependent on the phase of the worm's lifecycle. What are the two phases, and which is more concerning?

1. Enteral phase: within the GI → mostly asymptomatic but may have transient diarrhea and nausea 2. Parenteral phase: outside of the GI → 2 weeks post infection can develop myalgia and other severe clinical signs. More concerning--potentially fatal, depending on the location of the encysted larvae.

Capillaria (Eucoleus) eggs appear very similar to Trichuris eggs. They are both lemon-shaped, have bipolar plugs, and contain a single cell when passed in feces. What are fourdifferences that allow us to distinguish Eucoleus from Trichuris?

1. Eucoleus (Capillaria) eggs are much smaller than Trichuris. 2. Eucoleus eggs are asymmetrical, whereas Trichuris is very symmetrical. (Both plugs in line with one another for Trichuris but not aligned in Eucoleus) 3. Trichuris eggs have a smooth-walled shell and are usually browner than Eucoleus (Eucoleus is more clear to golden-brown) 4. Trichuris eggs have ridges on their plugs (like a plastic bottle), whereas Eucoleus eggs do not.

Match the species of Capillaria to the descriptions below: 1. _______________: causes bronchial capillariosis in domestic and wild carnivores (dogs, cats, fox) 2. ______________: causes nasal capillariosis in domestic and wild carnivores (dogs, fox) 3. ______________: causes urinary capillariosis in domestic and wild carnivores (dogs, fox)

1. Eucoleus aerophilus (aerophilus = lung-loving) 2. Eucoleus boehmi 3. Pearsonema plica

Describe 4 components that contribute to the epidemiology of Parascaris equorum.

1. Fecund females (200,000 eggs per day!) 2. Long-lived eggs: thick shells and can survive on pasture or in stable for many years 3. Pre-parasitic development: temperature-dependent (infective stage may develop in < 2 wks) 4. Seasonal transmission between yearlings and foals

1. The drug of choice for treatment of Trichuris infection in dogs is ______________. 2. The drug of choice for treatment of Eucoleus infection in dogs is ______________. 3. Why is distinguishing between these two genera to make a correct diagnosis crucial?

1. Fenbendazole 2. Ivermectin 3. Ivermectin can treat both Trichuris and Eucoleus infections, but Eucoleus CANNOT be treated with fenbendazole. Misdiagnosing Trichuris when it is Eucoleus can result in treatment that is ineffective for the animal.

1. _________ is the drug of choice to treat Aelurostrongylus abstrusus infection. 2. __________ can be administered as well to treat clinical signs during recovery by reducing the severity of lung lesions caused by larval migration.

1. Fenbendazole 2. Prednisone

Match each Filaroides species with the description below: 1. ___________: tracheal and bronchial nodular worm--produces hemorrhagic or granular, wart-like nodules in the trachea and bronchi of dogs and other canids 2. ___________: canine lungworm--infects the lung parenchyma of dogs and other canids

1. Filaroides osleri 2. Filaroides hirthi

Name the 4 species that have L1 larvae in the feces of dogs.

1. Filaroides sp. (osleri and hirthi) 2. Angiostrongylus vasorum 3. Aelurostrongylus abstrusus 4. Crenosoma vulpis

HOT species Three parasitic species affecting different physiological processes. which cause: 1. Gastritis - 2. Diarrhea - 3. Starvation - 4. Anemia -

1. Gastritis - O 2. Diarrhea - O,T 3. Starvation - O 4. Anemia - H

Describe the life cycle of Toxocara canis through direct transmission in an immature puppy (< 5 weeks)

1. Immature pup (< 5 weeks) ingests infective eggs containing L2 larvae. 2. L2s hatch and migrate to the liver, then to the lungs. 3. L2s undergo tracheal migration (bc young pup): L2s molt to L3s and pass up the bronchial tree 4. L3s are swallowed in the pharynx 5. L3s molt to L4s in the stomach 6. L4s molt to adults in the small intestine, where they mate and produce eggs that are passed in the feces.

1. The life cycle of Metastrongylus sp. is belived to be (direct/indirect). 2. The intermediate host is believed to be the __________. 3. The infective stage of Metastrongylus involves the intermediate host containing ____ larvae. 4. When eggs are shed into the environment from pig feces, they contain ____ larvae.

1. Indirect 2. Earthworm 3. L3 4. L1

1. The life cycle of Angiostrongylus vasorum is (direct/indirect). 2. The intermediate hosts are ___________. 3. Paratenic hosts are _______. 4. The infective stage is considered to be an intermediate or paratenic host containing ____ larvae. 5. Upon ingestion of the intermediate/paratenic host, ____ larvae migrate to the ____________, where they molt to adults. 6. Adults then migrate to the _______ and _________, where they lay eggs. 7. _____ larvae are released into the __________. They are then coughed up, swallowed, and passed through the feces.

1. Indirect 2. Mollusks 3. Frogs 4. L3 5. L3, visceral lymph nodes 6. Pulmonary arteries, lungs 7. L1, airways

1. The life cycle of Aelurostrongylus abstrusus is (direct/indirect). 2. The intermediate hosts are _________. 3. Paratenic hosts are ________ and ________. 4. The infective stage is considered to be the intermediate or paratenic host containing an ____ larvae. 5. Female adult worms deposit eggs in "nests" in the host __________. 6. ____ larvae are released into airways, coughed up, swallowed, and passed out in the feces.

1. Indirect 2. Snails 3. Rodents, birds 4. L3 5. Lung parenchyma 6. L1

1. Protostrongylus rufescens and Muellerius capillaris are both lungworms of small ruminants. Their life cycle is (direct/indirect). 2. The intermediate hosts are _________, which become infected after ingestion of ____ larvae in the feces. 3. The infective stage is considered to be an intermediate host containing _____ larvae.

1. Indirect 2. Snails, L1 3. L3

1. The life cycle for Parelaphostrongylus tenuis is (direct/indirect). 2. The intermediate hosts are ________, which become infected after ingestion of ____ larvae in the feces of the definitive host. 3. The infective stage is considered to be the intermediate host containing ____ larvae. 4. Upon ingestion of the intermediate host, these larvae move through the ____________ and travel along ___________ to get to the ________. 5. Females lay eggs in ___________ tissues. 6. ____ larvae enter the bloodstream and migrate to the _______. 7. These larvae are then coughed up, swallowed, and shed in the feces of the definitive host.

1. Indirect 2. Snails, L1 3. L3 4. Digestive tract, spinal nerves, brain 5. Meningeal 6. L1, lungs

Briefly describe the 3 infection routes of Toxocara canis (an Ascarid).

1. Indirect: dog ingests paratenic host infected with hypobiotic T. canis 2. Direct: dog ingests infective egg 3. Vertical transmission: transmission to offspring through placenta (prenatal transmission) or milk (transmammary transmission)

Pathogenesis of Stephanurus dentatus adult:

1. Inflammation and thickening of the kidney and ureter 2. Green pus around kidney

Life cycle of Stephanurus dentatus: 1. Routes of Infection • _____ • _____ • _____ 2. Immediate moult to L4 and migration to the ____ via blood 3. Final moult in ____ parenchyma (3 months) 4. Migrate through peritoneum to the ____ 5. Adults complete development in ____ cysts 6. Eggs passed in ____

1. Ingestion of L3's, Ingestion of infected earthworms (facultative intermediate hosts), Skin penetration by L3's 2. liver 3. liver 4. kidney 5. kidney 6. urine

Eucoleus (Capillaria) sp. life cycle: 1. The infective stage of the egg is when it contains an ____ larva. (Eggs are very resistant in the environment) 2. Larvae hatch in the ___________ and penetrate the __________. 3. Larvae enter the ____________ and migrate to the ________. 4. Adults mature, mate, and produce eggs (final location dependent on species).

1. L1 2. Small intestine, mucosa 3. Bloodstream, lungs

Exsheathment of hookworms: 1. L2 skin retained as a form-fitting sheath around ____. Protects larvae in the external environment 2. L3 cast off the sheath soon after entering the ____

1. L3 2. host

How do adult Dioctophyma renale worms cause organ damage?

1. Large adults cause pressure necrosis in the kidney, leading to destruction of the renal parenchyma 2. Females that lay eggs in the abdominal cavity can cause liver lesions, hemoperitoneum, and peritonitis.

1. What is the predilection site for Trichuris? 2. Clinical signs are rare, but when present, what do we typically see with heavy infections? 3. Who is the most susceptible to heavy Trichuris infections?

1. Large intestine (cecum and colon) 2. Bloody diarrhea, anemia 3. Young animals

Describe the clinical signs seen with light, moderate, and heavy infections of Aelurostrongylus abstrusus.

1. Light: generally asymptomatic 2. Moderate: can cause clinical disease! Cough, anorexia 3. Heavy: can be FATAL! Cough, dyspnea, and polypnea

What pathologies are typically seen in Ascaris suum infections in pigs?

1. Liver: "milk spot" lesions that represent granulomas and fibrosis 2. Lungs: pneumonia and cough due to L3 migration 3. Small intestine: in heavy infections, diarrhea and weight loss (wasting) 4. RARE: intestinal obstruction and rupture, obstruction of bile duct

groups of parasites that use indirect hosts?

1. Many nematodes 2. Vast majority of cestodes 3. ALL trematodes

Drugs are available to treat Protostrongylus rufescens and Muellerius capillaris infections: 1. Muelleris capillaris is treated with injectable _____________ in sheep and topical _________ in goats. 2. Protostrongylus rufescens is treated with ____________.

1. Moxidectin, eprinomectin 2. Fenbendazole

Describe the pathology that may be seen in each stage of Parascaris equorum in foals: 1. Migrating larvae in the liver 2. Migrating larvae in the lungs and bronchi 3. Adults in small intestine

1. NO clinical signs, white spots on liver on necropsy 2. pneumonia, nasal discharge, coughing 3. RARE: impaction, peritonitis, death

1. Eucoleus (Capillaria) boehmi is a parasite of the _________ that was originally described in foxes but can infect dogs. 2. Light infections are most common and are often ______________. 3. Severe infections in dogs can cause chronic ___________, as well as secondary bacterial infections caused by lesions formed from the parasites. The presence of a ____________ is indicative of bacterial infection. 4. There is ONE case of ___________ reported in a dog. Even though there is only one reported case, this tells us that it's possible!

1. Nasal sinuses 2. Inapparent (asymptomatic) 3. Rhinitis*, purulent discharge 4. intracranial migration (infection to the brain) (*chronic serous nasal discharge and reverse sneezing)

What factors reduce parasite success?

1. No hosts 2. Wrong host 3. *Immune host* 4. Dead Hosts shed no eggs! 5. Anti-helminthic drugs 6. Competitors - other species/same species (concomitant immunity) 7. External environment - too cold, too dry

characteristics of a stronglye-type egg

1. Oval-shaped 2. Thin, transparent shell 3. Contains developing embryo or larva, depending on time in the external environment

Describe the life cycle of Ascaris suum.

1. Preparasitic phase: thick-shelled, ovoid eggs are shed into the environment and mature into infective stage (L2 larvae) after 3-6 weeks. 2. If indirect life cycle: paratenic host (earthworm or dung beetle) ingests infective egg, the egg hatches in the gut, and infective larvae go to tissues (NO further development). 3. Parasitic phase is initiated by ingestion of an egg (direct life cycle) or an infected paratenic host (indirect life cycle). 4. Egg either hatches in the small intestine (direct life cycle), or L2 larvae are released into the small intestine (indirect life cycle). 5. L2 larvae penetrate the gut wall and use the portal vein to enter the liver. 6. L3 enters the lungs and undergoes tracheal migration: migrate to bronchi and trachea, then are coughed up and swallowed 7. L3 enters small intestine and molts to L4s, which molt to immature adults, and then mature into egg-laying adults.

Describe 5 components that contribute to the epidemiology of Ascaris suum.

1. Prolific females (200,000 eggs per day!) 2. Egg development takes 3-6wks and is temperature-dependent 3. Resistant, sticky eggs (rough surface) that can persist in the environment 4. Flies may spread eggs 5. Migration in ruminants and humans (zoonotic!)

What are the three main clinical signs of Oxyuris equi infection, and what causes them?

1. Pruritis: due to egg masses causing perianal irritation 2. Tail rubbing: due to pruritis 3. Loss of hair: due to tail rubbing ("rat-tail" appearance)

Current control strategies for Haemonchus

1. Reliance on strategic drenching programs 2. Levamisole - but resistance to every drug 3. Rotational grazing 4. Limited use of breeding technologies (No effective vaccines)

1. Eucoleus (Capillaria) aerophilus is primarily a parasite of the ______________ of foxes, although other hosts, such as raccoons, dogs, and cats, are susceptible. 2. Light infections account for most cases and are usually ____________. 3. Severe infections most commonly occur in _______ animals and show signs of ___________ disease.

1. Respiratory tract 2. Inapparent (asymptomatic) 3. Young, respiratory* (*cough, nasal discharge, dyspnea, tracheitis/bronchitis, and sometimes pneumonia)

Initiating factors in arrested development

1. Seasonal influences on infective larvae on pasture. 2. Host immune responses inhibiting the normal development of the parasitic phase of the life cycle. 3. Competition - presence of adult worms causes inhibition of incoming infective larvae which go into arrest until the adult worm population decreases in number or is eliminated.

Life cycle if Ancylostoma caninum

1. Skin penetration by L3/oral ingestion--> blood circulation--> tracheal migration--> intestine 2. Skin penetration by L3/oral ingestion--> blood circulation--> mammary tissue -->LACTOGENIC (TRANSMAMMARY) TRANSMISSION TO PUPS(NO TRACHEAL MIGRATION) --> intestine

1. Who are the definitive hosts of Protostrongylus rufescens and Muellerius capillaris? 2. What is the predilection site for each species? 3. Most cases of infection are asymptomatic, but heavy infections may cause clinical disease. This is especially true for which of these species and in which host?

1. Small ruminants (sheep and goats) 2. P. rufescens: smaller bronchioles; M. capillaris: lungs (both are LUNGWORMS) 3. M. capillaris in goats

who are the Large Strongyles?

1. Strongylus vulgaris 2. Strongylus equinus 3. Strongylus edentatus 4.Triodontophorus

1. How is Dioctophyma renale infection treated? 2. How is it prevented?

1. Surgical removal or adult worms from abdominal cavity and/or complete removal of the affected kidney. No drug treatments available. 2. Don't feed dogs raw or undercooked fish or frogs (paratenic hosts). Also limit opportunity for pets to acquire infection from intermediate or paratenic hosts.

1. Who are the definitive hosts for Metastrongylus sp.? 2. What is the predilection site? 3. What do heavy infections cause, and who is the most susceptible?

1. Swine (domestic and wild pigs) 2. Bronchi and bronchioles (LUNGWORM) 3. Respiratory disease, young pigs

What are two adaptations of Ascarids like Toxocara canis that greatly contribute to its success as a species?

1. T. canis females are very fecund and can produce up to 200,000 eggs per day! (more than many other worms) 2. T. canis eggs in the infectious stage can survive in the infectious form for 5-7 years. (Very difficult to rid of in environment, consider them there for life!)

1. Larvae of Toxascaris leonina develop exclusively in what part of the definitive host? 2. How does this affect the PPP (pre-patency period) in comparison to T. canis and T. catis?

1. The gut (L2s hatch and invade intestinal mucosa, where they molt to L3s, return to the lumen, and mature into adults in the small intestine) 2. PPP is longer because larvae take longer to develop in the gut

describe the life cycle of dictyocaulus viviparus

1. There are no eggs in the feces. The L1s come alive in the feces. 2. relationship with fugus Pilobolus: dictyocaulus viviparus sits on the top of the fungus and when the fungus spores larvae are disseminated in the environment

1. How is the life cycle of Trichinella unique? 2. How is a Trichinella infection acquired?

1. There is NO free-living stage. Both adult and larval stages occur in sequence in the same host (Predator is also a prey!) 2. Host ingests raw or undercooked meat that contains encysted L1 larvae (infective stage, larvae present in striated muscle).

What are two ways Trichinosis can be prevented? What should we be aware of when choosing a prevention method?

1. Thoroughly cook meat (145F internal temp) 2. Freeze meat for several weeks → BEWARE! Some species of Trichinella are freeze-resistant

There are 4 major Ascarids of dogs and cats (and raccoons): Toxocara canis, Toxocara catis, Toxascaris leonina, and Baylisascaris procyonis. 1. Which is the only one with NO tracheal migration and NO somatic migration? 2. Which is the only one that CANNOT undergo vertical transmission? Which one is unlikely to undergo vertical transmission? 3. Of the ones that undergo vertical transmission, which ones can undergo prenatal (placental) transmission, and which ones can undergo transmammary transmission?

1. Toxascaris leonina (T. canis, T. catis, and B. procyonis can undergo both tracheal and somatic migration) 2. Toxascaris leonina CANNOT undergo vertical transmission. Baylisascaris procyonis is UNLIKELY to undergo vertical transmission. 3. Only Toxocara canis can undergo prenatal (placental) transmission, whereas both Toxocara canis and Toxocara catis can undergo transmammary transmission.

There are 4 major Ascarids of dogs and cats. Match each one to its definitive host: 1. ____________: dogs (present worldwide) 2. ___________: cats (present worldwide) 3. ___________: dogs and cats (even more broadly distributed due to wider thermal tolerance, both hot and cold) 4. ___________: dogs and raccoons (widespread in US and Canada, highest in Northeast, Midwest, and Western US. Can infect up to 80% of surveyed raccoons)

1. Toxocara canis 2. Toxocara catis 3. Toxascaris leonina 4. Baylisascaris procyonis

Match the visual description of the egg to its small animal Ascarid: 1. ____________: dimpled surface that looks like a golf ball. Surface remains bumpy when you focus up and down 2. ___________: bumpy features within the egg, but the entire surface is smooth when you focus up and down 3. ___________: large, brown egg with large blobs of proteinaceous material. This egg looks quite distinct from the other eggs you've looked at.

1. Toxocara canis (if from a dog; or T. catis, if from a cat) 2. Toxascaris leonina 3. Baylisascaris procyonis

Organisms that transmit parasite directly from host to host

Vector

Ronnie is a 5y MC German Shepherd that presents to your clinic after vomiting up a large worm (~11cm in size) with clear fluid. You check the worm under the microscope and observe a mouth with 3 lips and cervical alae. 1. What is this parasite, and how do you know? 2. What route of transmission is the most likely?

1. Toxocara canis. Baylisascaris procyonis also infects dogs but is ruled out because it does not have cervical alae and tends to be larger than T. canis (15-20cm) 2. The most likely cause is that Ronnie ingested a paratenic host. Direct ingestion is less likely because Ronnie is an adult dog, and if he were to ingest an infective egg, the larvae would most likely undergo somatic migration/hypobiosis, and we would probably not see adult worms.

How is Ascaris suum treated and controlled?

1. Treatment: many drugs available that target adult worms 2. Control: raise pigs on concrete and remove feces (still may be present to some degree). Breed resistant pigs

What are three ways Dioctophyma renale infection can be diagnosed?

1. Urine sedimentation (adults live in kidney) 2. Most common: distended right kidney on radiograph or ultrasound 3. Laparotomy: adult worms free in abdominal cavity

Control of DICTYOCAULUS VIVIPARUS

1. Vaccination in Europe - where clinical disease is frequent (Vaccinated animals carry light infections) 2. Anthelmintics in the USA

Toxocara canis and Toxocara catis both have three routes of infection: indirect (paratenic host), direct, and vertical transmission. What are two differences observed within the infection routes of these two species?

1. Vertical transmission: T. catis can undergo vertical transmission but only through milk (transmammary), NOT through the placenta. T. canis can be transmitted through both milk and the placenta. 2. Direct transmission: T. catis appears to undergo both somatic and tracheal migration, regardless of age, whereas somatic vs tracheal migration in T. canis is age-dependent.

1. Who is the definitive host for Parelaphostrongylus tenuis? 2. What is the predilection site? 3. How can this parasite cause serious disease?

1. White-tailed deer 2. Meninges 3. Definitive host infection is usually asymptomatic, but if caught in an abnormal host, it can cause 100% fatal neurological disease.

life cycle of Ostertagai Ostertagi including arrested development (not sure if we need to know this or it was an example)

1. acute onset of disease in spring 2. larvae arrest at the L4 in the fall and emerge the following spring 3. peripartuient rise or "spring rise" in egg counts

Pathogenesis of Strongylus vulgaris 1. larvae cause inflammation in _____ 2. rarely aneurysms and thinning of walls 3. fever, inappetence, colic (possibly fatal) 4. _____ cause intestinal ulcers, bleeding and scarring due to feeding on the mucosa

1. arterial walls 4. Adults

Life cycle of Strongylus vulgaris: Common to all equine strongyles 1. Adults live in _____, eggs passed in feces (L1) 2. Development of L3 takes ___ weeks 3. L3 penetrate ____mucosa Unique to S. vulgaris 4. L4 migrate to endothelium in the ______ 5. Molt to ____ (young adult) in 2-3 months 6. Return to intestine via ______ Common to all equine strongyles 7. Nodules form in the mucosa that burst to release adults into gut

1. cecum 2. 2 3. intestinal 4. cranial mesenteric artery 5. L5 6. arterial lumina

Oxyuris equi: 1. Adults live in the ______ and _______ of horses. 2. Eggs are shed onto _____________. 3. L4s feed on __________. 4. Adults feed on _________.

1. cecum, colon 2. perianal skin 3. mucosa of the colon 4. intestinal contents

Diagnosis of DICTYOCAULUS VIVIPARUS

1. clinical signs (seasonal occurance) 3. L1s in feces of clinical hosts-but can have clinical disease before this stage 4. necropsy

Life cycles of Oesophagostomum spp.: 1. Adults live in the _____ 2. "Strongyle-type"eggs in feces 3. Free-living larval development is quick 3-7 days to ____ at 22-30 C 4. L3's can live for months, surviving ____. 5. Infection by ingestion of ____ L3's 6. L3s _____ in small intestine 7. Penetrate the mucosa of small and large intestine (large intestine only in pigs), molt to L4's in the ____ 8. Can undergo hypobiosis 9. L4's emerge, pass to the ____

1. colon 3. L3 4. winters 5. ensheathed 6. exsheath 7. nodules 8. colon

different stages of the nematode life cycle

1. contamination 2. development 3. infection

OSTERTAGIOSIS Clinical signs

1. diarrhea- profuse and watery 2. anorexia but still eating 3. dehydration 4. weight loss 5. sub-mandibular edema (bottle jaw) 6. anemia

1. The Trichuris life cycle is (direct/indirect). 2. The infective stage of the egg is when it contains an ____ larvae. 3. It takes approximately ___ month for the egg to reach the infective stage. 4. When does the egg hatch?

1. direct 2. L1 3. 1 4. When swallowed by a suitable host

Life cycle of Ascaridia galli (in chickens and turkeys): 1. Eggs are shed in ________ and distributed throughout the environment. 2. Eggs develop to the infectious stage after approximately ____ weeks. 3. Eggs can survive up to ____ months if moist and shaded. 4. Host ingests infective eggs, and larvae mature to the adult stage in the _____________. 5. Adults mate and produce eggs that are then shed into the environment via ________.

1. feces 2. two 3. three 4. small intestine 5. feces

Writing Parasite Names: 1. Scientific names of species (animal or plant) are _____ 2. Genus name starts with _____ letter and species name is ____ 3. Species abbreviation = sp. (singular) or spp. (plural)

1. italicized 2. capital, lowercase

efficient treatment timing regimes for Haemonchus infections

1. just the lambs most affected 2. strategic prophylactic timing at weaning and 6 weeks later 3. therapeutic- those that are sick (every 4 weeks- not as effective)

Life Cycle of CYATHOSTOMES - Small Strongyles: Preparasitic: 1. Identical to _____ - Direct (free-living larvae) - During mid summer L3's develop in 2 weeks Parasitic: 2. No ______: L3 to L4 development inside mucosa of _____ 3. pre-patent period is 6-12 weeks but there may be arrested development in _____ in temperate climates

1. large strongyles 2. migration, large intestine 3. winter

2 reasons why ancylostoma caninum is extremely pernicious

1. patency occurs seven days earlier than it normally would 2. blood loss can occur before patency

1. Adult Eucoleus (Capillaria) worms are located in the ___________ system of the definitive host. The specific location depends on the species: 2. Adult Eucoleus aerophilus worms reside in the ___________* of __________, __________, and the __________. 3. Adult Eucoleus boehmi worms reside in the ___________* of the ______________. (* = layer of tissue)

1. respiratory 2. epithelium, bronchioles, bronchi, trachea (aerophilus = lung-loving) 3. mucosa, nasal sinuses

Trichostrongylidae life cycle: 1. Adult is found in the ___, that makes eggs and contaminates the pasture 2. One they hatch, they give rise to the larval stage that is ____ and motile 3. L3/L4 are ingested and go through the gut to find their home in the ___ or ___, where they become adults

1. ruminant 2. free-living 3. stomach, small intestine

OSTERTAGIOSIS causes Growth of larvae in gastric glands: 1. Erosion of _______ - replaced with undifferentiated cells 2. Change in abomasal ____ 3. Permeable ____ (Elevated plasma pepsinogen, Hypoalbuminemia) 4. ____ diarrhea

1. secretory epithelium 2. pH 3. mucosa 4. Osmotic

Life cycle of hookworms: 1. Eggs are laid in the ____ 2. Excreted in the feces 3. Eggs hatch and larvae develop to infective ___ stage 4. Infective larvae enter host through ___ or ___ 5. Larvae follow ___ migration and mature to adult stage

1. small intestine 3. 3rd 4. mouth or skin 5. tracheal

There are 4 major Ascarids of dogs and cats (and raccoons): Toxocara canis, Toxocara catis, Toxascaris leonina, and Baylisascaris procyonis. 1. What is the predilection site of each? 2. Which of these are zoonotic? 3. Which of these have a direct life cycle, and which have an indirect life cycle? 4. Which ones can utilize transport hosts (paratenic hosts)? 5. Which ones have cervical alae?

1. small intestine (ALL 4) 2. ALL 4 3. ALL 4 have DIRECT life cycles (None for indirect technically, but can use paratenic hosts) 4. ALL 4 can use paratenic hosts 5. T. canis, T. catis, and T. leonina. B. procyonis does NOT have cervical alae

You perform a necropsy of a dog with a severe Ascarid infection. 1. Where do you expect to find most of the worms? 2. How do the worms stay in this site? 3. How does this mechanism contribute to pathogenesis? 4. What precautions should you and your team take during the necropsy?

1. small intestine (predilection site) 2. During life, peristalsis tries to push the worms down the small intestine. Ascarids coil themselves to maximize surface area for contact with the intestinal wall to gain traction, allowing them to migrate against peristaltic flow and stay in the small intestine. 3. Ascarids damage the small intestine by constantly rubbing against the intestinal wall. They can also blunt villi and prevent food absorption. Lastly, the worms can become knotted and cause obstruction. Dogs can have slower weight gain, swelling, edema (pot-belly appearance), and even intestinal rupture. 4. Wear PPE! Small animal Ascarids are ZOONOTIC!

Life cycle of Syngamus trachea: 1. Adult worms in the____ of domestic birds 2. Bi-operculate eggs coughed up, swallowed and passed in ____ of hosts 3. L3 develops inside the egg 4. Infection by _____ of L3 in egg, hatched L3, or L3 in paratenic hosts 5. L3 penetrate intestine and migrate to _____ 6. Pre patent period is 18 days, then the live permanently in ____

1. trachea 2. feces 4. ingestion 5. lungs 6. copula

A dog that consumes an infectious Ascarid egg such as Toxacara canis can have one of two outcomes in the Ascarid lifecycle. 1. One is _________ migration, where L2 larvae migrate to the lungs, are coughed up, and swallowed. 2. The other is _________ migration, where L2 larvae are not coughed up but instead enter systemic circulation and encyst into tissues where they become hypobiotic.

1. tracheal 2. somatic

OSTERTAGIOSIS- 2 clinical entities 1. Type I - most common in _____ cattle grazing contaminated pastures for the first time. 2. Type II - results from arrested ______ resuming development to immature adults and leaving gastric glands.

1. young 2. L4 larvae

Disease of both humans and animals

AMPHIXENOSIS

Disease restricted to humans that evolved from infections of lower animals

ANTHROPONOSIS

Consequences of arrested development: 1. Survival of nematodes when external conditions are hostile. 2. _____ development of large numbers of larvae may produce serious disease. 3. Arrested larvae are depressed metabolically and hence may be less susceptible to some ______

2. Synchronous 3. anthelmintics

Major features of the Trichostrongyles: 1. Small, hair-like 2. Large copulatory _____ 3. (buccal capsule/no buccal capsule)

2. bursa 3. buccal capsule (small)

General features of Strongyloidea: 1. Large-bodied worms 2. (bursate/non-bursate) 3. Buccal capsules 4. Direct life cycles 5. Migration in many species 6. Strongyle-type eggs except Syngamus 7. Predilection site = ______

2. bursate 7. large intestine

Life cycle of Strongylus equinus: 1. Ingestion of L3's 2. Exsheath in ____ 3. ____ to L4's (nodules) 4. Migrate to ___and stay for 6 to 7 wks 5. Migrate to ____ 6. Molt to ___ (16-17 weeks pi) 7. Return to _____

2. mucosa 3. Molt 4. liver 5. pancreas 6. L5's 7. large intestine

Disease of humans acquired from animals

ANTHROPOZOONOSIS

Approximately how long does it take for Oxyuris equi eggs to reach the infectious stage? Why is this such a short period of time?

3-5 days. Eggs are shed onto perianal skin, and the warmth of the skin significantly speeds up development to the infectious stage.

_____ is most pathogenic hookworm disease in dogs

A. caninum

what organs do Trichostrongyles infect?

Abomasum, stomach, small intestine

Where does the term Acanthocephalans come from?

Acanth - thorn Cephala - head

Dirofilaria immitis is found in different places depending on the stage in the life cycle. _________ are found in the heart and pulmonary arteries and __________ circulate in blood.

Adults; Microfilariae

________ spp are intestinal flukes in the family Diplostomatidae (infect definitive hosts through consumption of secondary intermediate hosts). They can be pathogenic and are primarily a wildlife disease (raccoons!) though they can affect dogs and cats.

Alaria

Mesocercaria are a special larval stage found in intermediate, paratenic hosts. They are a characteristic of what trematode species?

Alaria spp (intestinal flukes in the family Diplostomatidae)

Both alive and dead adult dirofilaria immitis are capable of causing pathogenesis in the dog. Explain how?

Alive: physical obstruction and trauma to endothelial lining of vessels, heart chambers, and valves by adult worms leading to pulmonary hypertension and right side failure. villous proliferation of endothelium Dead: Dead and dying heartworms induce thrombosis, blood flow obstruction, strong inflammatory response in the distal vasculature *The longer they remain in an animal, the greater the damage to the cardiopulmonary system and the greater the risk of illness and death

Crenosoma vulpis infection may sometimes be misdiagnosed as what?

Allergies (cause chronic cough that can mimic allergic respiratory reactions)

example of hookworm that has a transmammary route in dogs and cats

Ancylostoma caninum

Hookworms with cutting buccal teeth Subfamily _______

Ancylostominae

What is the agent of French heartworm?

Angiostrongylus vasorum

Main clinical signs of Thelazia sp. infection in animals and people.

Animals: mild ocular symptoms Humans: generally mild (unilateral)

A tapeworm of horses found in the small intestines. Relatively non-pathogenic

Anoplocephala magna, Paranoplocephala mamillana (aka Anoplocephaloides mamillana)

A tapeworm of horses. Found in the cecum and in the ileum clustered near the iliocecal valve. Adults can be PATHOGENIC, causing ulceration and associated inflammation, leading to serious, persistent diarrhea.

Anoplocephala perfoliata

______________ is a family of cestodes that mainly affect horses and donkeys. They have a terrestrial life cycle using mites as an intermediate host.

Anoplocephalidae *order cyclophyllidea

a temporary halt in the parasitic phase of development at a specific point in the nematode life cycle

Arrested development

Prenatal (placental) transmission of Toxocara canis occurs when hypobiotic larvae in the mother become activated in response to hormone levels ~41-45 days into pregnancy. How can these larvae sense this stage of pregnancy?

Arrested larvae have prolactin receptors similar to that of dogs, so they can sense this point in the dog's pregnancy.

Ascaridia galli eggs appear slightly different than other Ascarids. How do these eggs differ? What is one similarity A. galli eggs share with other Ascarids?

Ascaridia galli eggs are more oval and more clear than other Ascarid eggs (+ have a smooth surface). Like other Ascarids, Ascaridia galli eggs have a thick wall. (*Note: Ascaridia galli eggs appear more similar to Strongyle eggs than Ascarid eggs, but can be differentiated as an Ascarid by its thick wall, in contrast to Strongyle eggs that have thin walls.)

Eggs of this order of roundworms are round, thick-walled, brown, and contain a single cell when passed in feces.

Ascaridida

You pull a large roundworm from your patient and observe 3 lips surrounding its mouth--one dorsal and two ventral. This is a defining feature of what order of parasites?

Ascaridida

Order that contains some of the largest nematodes of domestic animals

Ascarids (Order Ascaridida)

You pull a roundworm from your patient who is a raccoon and observe 3 lips surrounding its mouth. You know this is a characteristic feature of Ascarids, and without further testing are able to identify the type of Ascarid. How are you able to do this?

Ascarids are relatively host-specific. Most animals have just one Ascarid that they are typically infected by. (Identification of an Ascarid in a raccoon tells you that it is the Ascarid that infects raccoons, such as Baylisascaris procyonis)

"Milk spots" on the liver are characteristic of what swine parasite? What are the "milk spots" indicative of?

Ascaris suum. Due to migrating larvae in the liver that cause granuloma formation and subsequent fibrosis, giving a mottled white appearance that looks like "milk spots."

Hymenolepis nana is a cestode in the family Hymenolepididae. It is not usually pathogenic but it's life cycle does have one (disturbing lol) and unique feature. What is it?

Autoinfection! Eggs can hatch in the intestine and complete the life cycle, all in the definitive host and in the absence of an intermediate host.

At what point in a dog's life does Toxocara canis larvae almost exclusively undergo tracheal migration during its life cycle? At what point does it almost exclusively undergo somatic migration?

Before 5 weeks of age, T. canis exclusively undergoes tracheal migration, whereas after 6 months of age, T. canis exclusively undergoes somatic migration. Between 5 weeks and 6 months of age, there is a mix of the two.

appearance of Syngamus trachea eggs

Bioperculate egg in feces

What is the agent of Blackhead disease, and where does it get its name from?

Blackhead disease is caused by the protozoan parasite Histomonas meleagridis (carried by transport host Heterakis gallinarum). Its name comes from the characteristic darkening of the facial regions of turkeys due to reduced blood flow as a result of impaired blood synthesis.

One possible explanation for a ANTIGEN NEGATIVE and Microfilariae POSITIVE heartworm test is blocked antigen. How can you determine if this is the cause?

Blocked antigen is the formation of antigen-antibody complexes which blocks the test from working. Immune-complex dissociation (ICD) method!!!!!! breaks up the complexes and allows the antigen test to work

Hookworms with cutting plates Subfamily _____

Bunostominae

How do you diagnose Thelazia sp. infection?

By species identification. You can identify the adult worm in the conjunctival sac by morphological examination or via molecular methods

The prepatent period of dirofilaria immitis is 5-6 months. Why might this be problematic?

By the time you are first able to detect infection there are already adult worms in the heart causing problems for the animal (physical obstruction of vessels, chambers, and valves)

Classic clinical sign of Habronema sp. and Draschia sp.

CUTANEOUS HABRONEMIOSISIS = persistant cutaneous granulomas *Initial rapid production of granulation tissue that refuses to resolve during fly season *Subsequent appearance of caseocalcareous nodules in this granulation tissue

Genus of Nematodes that consist of very fine and small worms that are commonly known as "hairworms." Because of their size, these worms are almost never seen, even on necropsy and histopath.

Capillaria (includes Eucoleus, Pearsonema)

Why should you avoid raising turkeys at sites previously occupied by chickens?

Chickens infected with Heterakis gallinarum shed eggs through the feces, which can survive in the environment for two years! This is especially important for turkeys because H. gallinarum serves as a transport host for the protozoan parasite Histomonas meleagridis, an important turkey pathogen that can cause high mortality.

Why should you NEVER raise chickens and turkeys together?

Chickens often serve as a reservoir host for transmission of Histomonas meleagridis to turkeys, a protozoan parasite that can cause high mortality to turkeys!

2 species living together and neither "loses" or "win"

Commensalism

_____________ cestode segments have no opening for release of eggs and therefore produce gravid segments; _____________ cestode segments do release eggs and produce senile (empty) segments.

Cyclophyllidean; pseudophyllidean

A small tapeworm of dogs (4-5 segments) in the family Taeniidae. Scolex has an armed rostellum and 4 suckers. Larval tapeworm of several hosts, including humans. Causes Hydatid Disease in humans

Echinococcus E. granulosus or E. multilocularis *order cyclophyllidea

__________ is the species of Dracunculus sp. that was near extinction thanks to an international campaign, however additional cases began to reappear in ________

D. medinensis aka Guinea Worm; Chad *inspiration of the medical symbol

type of host: Adult or sexually reproductive process occurs in host

Definitive Host

Distinguishing adult trematodes! Within the liver and bile duct you find a SMALL, LANCET-LIKE trematode. Whomst is it?

Dicrocoelium

_____________ are liver flukes found in bile duct of sheep, cattle, and pigs. They have a terrestrial life cycle with snail and then ant intermediate hosts. There is no parenchymal migration of this parasite and clinical disease is associated with bile duct ______________.

Dicrocoelium dendriticum; fibrosis and cirrhosis

This species is the largest nematode of domestic animals and is commonly known as the "Giant Kidney Worm" because it can reach up to 1 m in length and 1 cm in diameter in the kidney. These worms are also deep red-purple in color.

Dioctophyma renale

_____________ is a cestode in the order Pseudophyllidea. It has an aquatic life cycle that requires a copepod and then fish interemediate host. Found in dogs around the Great Lakes - seen quite often in seals and dolphins.

Diphyllobothrium latum

_________________ is a ZOONOTIC tapeworm of dogs and cats in the family Dilepididae. It is spread by fleas and biting lice and develops quickly in definitive host. It is only occasionally found in humans but it is the MOST COMMON human tapeworm in the US.

Dipylidium caninum (double-pored dog tapeworm) *order cyclophyllidea

define type of life cycle: direct? indirect?

Direct: Only 1 host needed Indirect: 2 or more hosts needed

The most important parasite of dogs in North America

Dirofilaria immitis *high incidence in southeastern region and Mississippi River Valley

One of the most deadly parasites of dogs. Parasites of the pulmonary arteries and right ventricle of dogs, cats, and ferrets. Females longer than males. Simple morphological features: males have a spirally coiled posterior end

Dirofilaria immitis aka heartworm

definite host of nematodes

Domestic animals

Parasites of the subcutaneous tissues of carnivores and humans. This group includes the Guinea Worm

Dracunculus sp. *insignis: raccoons (RARE in dogs/cats) *medinensis: guinea worm

Describe physaloptera sp. eggs on floatation

Eggs are CLEAR and ELLIPTICAL. Have a smooth shell wall with a LARVA COILED INSIDE

How do schistosomes like schistisoma japonicum cause disease?

Eggs can remain in the host and cause chronic disease - form granulomas in the tissues

Briefly describe Paramphistomatidae's life cycle.

Eggs released into the environment, taken up by snail intermediate host. Cercaria becomes encysted on plants which are then ingested by ruminants. Fluke travels from duodenum to the rumen.

Where are adult Trichinella worms found in the definitive host?

Embedded in the mucosa of the small intestine (females deposit prelarvae directly into host intestinal mucosa)

how do you decide when to treat Haemonchus infections

FAMACHA-look at the conjunctiva (red-don't need to treat, the more pale the more likely you need to treat)

(T/F) Cestode/tapeworm segments are served by individual osmoregulatory and nervous systems.

False! All segments are served by common osmoregulatory and nervous systems which allows for rhythmic, coordinated movement.

(T/F) Dirofilaria immitis is not a parasite of economic importance in the US

False! Huge economic importance!!! Billions spent on heartworm prevention, diagnosis and treatment - MOST IMPORTANT PARASITE OF DOGS IN NA

(T/F) Heartworm disease only affects the cardiovascular system

False! It is a multiorgan disease impacting the heart, lungs, liver, and kidney

Distinguishing adult trematodes! Within the liver and bile duct you find a LARGE, LEAF-LIKE trematode. Whomst is it?

Fasciola hepatica

Trematode predilection sites in definitive hosts. Which trematodes go to the liver and bile duct?

Fasciola hepatica Fascioloides magna Dicrocoelium dendriticum Platynosomum fastosum

___________ is a ZOONOTIC fluke in the family Fasciolidae. They have leaf-like flattened shoulders and their eggs are operculate and unembryonated. They are capable of causing both acute and chronic disease primarily of the _____________.

Fasciola hepatica; liver

___________ is a LARGE fluke in the family Fasciolidae. Form cysts in the liver that connect to the bile duct. Deer are the normal host. In sheep and goats juveniles do not mature - continue to migrate.

Fascioloides magna

How is Metastrongylus sp. diagnosed?

Fecal floatation. Look for larvated eggs, but be sure to differentiate from other larvated parasite eggs found in swine manure (Strongyloides ransomi, Ascarops strongylina, Physocephalus sexalatus)

Diagnosis of physaloptera sp. Gastroscopy and ________________ (fecal exam).

Fecal sedimentation! *Eggs are high density - not reliably detected by fecal flotation

Diagnosis of Spirocerca lupi is done with gastroscopy to visualize the characteristic fibrotic nodules and ________________ (fecal exam).

Fecal sedimentation! *Eggs are high density - not reliably detected by fecal flotation

Name 4 anthelmintics that are approved for activity against swine lungworms (ie Metastrongylus sp.).

Fenbendazole, levamisole, ivermectin, and doramectin

Onchocerca spp. are within the superfamily ______

Filarioidea *within suborder Spirurida

A spasmodic attack of a hard, dry cough that is initiated by exercise or exposure to cold air is a characteristic clinical sign of what parasitic infection?

Filaroides osleri

Order Strongylida are ___ parasites that have a ____ type egg

GI, strongyle

Parasites of the stomach of horses and donkeys. Unimported stomach parasites. Adult worms stay remarkably close to the margo plicatus. Larvated eggs in feces.

Habronema sp. and Draschia sp. *Larvae common names: "swamp cancer," "bursatti," "summer sores," "esponja"

______ is the most important intestinal parasite of sheep and goats and other ruminants.

Haemonchus

Why can Haemonchus have a biotic potential of 5-10,000 eggs per day while Trichonstrongylus has 500-2000 eggs per day?

Haemonchus feeds on blood

You are a swine vet and diagnose a young pig with catarrhal enteritis secondary to heavy Trichuris infection. Knowing it's a pig with these clinical signs, what else should you consider when formulating your treatment plan?

Heavy Trichuris infection in pigs (and other helminths) may be associated with bacterial infections, such as C. jejuni. You may need to treat both to fully rid of disease.

clinical signs of Syngamus trachea disease

Hemorrhagic tracheitis with mucus production • "Gaping" • Shaking,gasping • youngbirds coughing, severe pneumonia, death

What species is the transport host of Histomonas meleagridis, a flagellated protozoan parasite that infects the cecum and liver and can cause high mortality in young turkeys?

Heterakis gallinarum

The larval stage of the tapeworm Echinococcus that may be found in the lungs or liver of livestock and humans

Hydatid cyst *Fluid aspirated from a hydatid cyst will show multiple protoscolices (size approximately 100 µm), each of which has typical hooklets = "Hydatid sand"

The cestode species that can undergo autoinfection - can complete the lifecycle in the definitive host in the absence of an intermediate host

Hymenolepis nana *order cyclophyllidea

Newborn puppies with heavy, vertically transmitted Toxocara canis infections can have up to 80% mortality and high morbidity in those who survive. What is the primary cause of this high mortality?

If an infection is heavy, there can be a lot of hemorrhage associated with lung migration. T. canis infections in immature pups almost exclusively undergo tracheal migration, causing significant lung damage.

Why is Trichuris reinfection common after treatment?

Infective eggs are very resistant! Animals confined to contaminated environments are very susceptible to reinfection.

type of host: There is required development of intermediate or larval stages

Intermediate Host

what is the indirect life cycle of a nematode?

Intermediate host required for development of pre-parasitic larvae 1. Definitive host ingests intermediate host 2. Intermediate host serves as a vector

Why is Angiostrongylus vasorum an important pathogen for dogs?

It can cause cardiopulmonary disease (aka French heartworm). Infection can induce clotting disorders and may result in subcutaneous or intracranial hemorrhage. (+ Ocular and CNS disease have also been reported)

What is the drug of choice for Strongyloides spp. in almost all animal species?

Ivermectin

How can you prevent reinfection of Parascaris equorum in foals?

Keep yearlings away from foals! Keep on separate pastures!

If Parelaphostrongylus tenuis infection requires consumption of L1 larvae in feces by the intermediate host (snails), why are we unable to diagnose this parasite with fecal floatation?

L1 larvae are only shed in the feces of the definitive host (white-tailed deer). P. tenuis rarely matures in the abnormal host, so no larvae are shed through the feces.

Why are Filaroides sp. so problematic with management of contaminated environments?

L1 larvae are passed through the feces or saliva and are IMMEDIATELY infective to another host, leaving no window of time to clean feces/saliva before potentially causing another infection.

Order Strongylida exist in what stages in the environment

L1-L3

stage of ancylostoma caninum that can feed on blood

L4

Clinical signs of Oxyuris equi infection can occur before patency. How so?

L4s feed on mucosal lining of the colon, causing erosions and ulcers. This occurs before egg production (and thus, patency).

The digenean parasite family Fasciolidae are commonly known as ______________

LIVER FLUKES

What is the predilection site of Oxyuris equi? Who is the definitive host?

Large intestine of horses

What causes the pot-bellied appearance of puppies that are infected with Toxocara canis?

Large numbers of adult worms coil up in the small intestine to maximize their surface area for contact with the intestinal wall in order to resist peristaltic forces. This not only causes tissue damage but partial or full obstruction that results in severe edema of the gut wall, giving the puppy a "pot belly."

Baylisascaris procyonis is a raccoon (+ dog) Ascarid that infects the small intestine. Why is this parasite an especially important zoonosis?

Large, neurotrophic larvae undergo somatic migration in many paratenic hosts, including humans, that can enter and infect the brain. Can be life threatening!

Why is the PPP (pre-patent period) of Toxocara canis and Toxocara catis generally shorter with paratenic and transmammary routes of transmission?

Larvae do not migrate outside of the GI tract (no tracheal migration). They are ingested and directly delivered to their predilection site (small intestine).

Clinical signs of physaloptera sp. infection?

MINOR CLINICAL SIGNIFICANCE in dogs and cats. May result in VOMITING and ANOREXIA *Adults are often viewed during ENDOSCOPY

____________ is an acanthocephalans found in the small intestine of pigs and of veterinary importance in S. America. It can be highly pathogenic and occasionally infects dogs and other mammals. Intermediate hosts include dung, may, and water beetles.

Macracanthorhynchus hirudinaceus

A herd of cattle are showing signs of neurological disease. When the farmer tells you the location of his pasture, you realize it is an area with a high population of white-tailed deer. How will you diagnose the problem? What do you recommend for the herd?

Make a presumptive diagnosis of Parelaphostrongylus tenuis. There is no specific diagnostic test. Clinical signs and epidemiology are used to make the diagnosis. Recommend euthanasia, as there is no treatment available, and neurological disease from this parasite is 100% fatal.

defining characteristic of a bursate nematode

Male tail in the form of a copulatory bursa that clasps the female during mating.

What is the suspected route of transmission of Filaroides sp. in young pups?

Maternal grooming (infective L1 larvae are passed through saliva)

2 species living together for the benefit of both

Mutualism

Trematode predilection sites in definitive hosts. Which trematodes go to the intestine?

Nanophyetus salmincola Alaria marcianae

___________ is a ZOONOTIC intestinal fluke in the family Troglotrematidae. Salmonids act as their second intermediate host. This parasite is host to Neorickettsia helminthoeca the cause of _____________

Nanophyetus salmincola; salmon poisoning

______ are round worms in the strict sense. They are elongate, cylindrical organisms, bounded by a non-cellular cuticle.

Nematodes

You do a fecal exam on a foal and notice round eggs with a dense, opaque, sticky protein coat. Knowing this is characteristic of Ascarids, you conclude the egg is likely Parascaris equorum. However, you also note a small number of eggs that contain a thick wall but do not have the characteristic dense protein coat. Your tech insists that the foal must be infected with another intestinal parasite. Do you agree?

No! 4-10% of P. equorum eggs can lose their coat, with the highest prevalence being just after the peak fecal egg count. Sometimes, we can see a mixture of parasites with and without the coat.

What clinical signs are most commonly seen with Trichuris infection?

None! Just a few worms are well-tolerated, and typically there is NO clinical disease. However, in heavy infections, severe disease can result (ie anemia, bloody diarrhea).

What are some possible interpretations of a ANTIGEN POSITIVE and Microfilariae NEGATIVE heartworm test?

OCCULT or AMICROFILAREMIC infection 1) Single sex (female) adult infection 2) Host immune responses 3) Early infections: occurrence of circulating antigen prior to microfilariae production 4) Elimination of microfilariae by administration of monthly preventives

An emerging ZOONOTIC filarial nematode. Parasite of domestic and wild animals whose location depends on SPECIES and HOST. Adults, although large, are likely to escape notice because they are intricately woven into the deep connective tissues (found in nodules). Once found, they are virtually impossible to isolate intact, so specimen bottles tend to contain many fragments of the midsection and very few ends.

Onchocerca sp.

____________ is an acanthocephalans rarely found in the small intestine of dogs and cats. The life cycle is largely unknown. There was a case reported in an infected dog from Texas.

Oncicola canis

Trichostrongylus can cause clinical disease alone, but especially so if found in association with _____ or ______.

Ostertagia, Haemonchus

Name the order of worms! - One or both sexes have a long, tapered tail (usually females) - Large intestine is the predilection site - Have direct life cycles - Host-specific - Generally not pathogenic

Oxyurida (Pinworms)

Trematode predilection sites in definitive hosts. Which trematodes go to the lungs?

Paragonimus kellicotti

The family of digenean parasites known as rumen flukes. They cause patent infection in sheep and cattle (also in deer, etc.) and adults are relatively harmless. However a high infective dose can lead to disease as worms migrate from small intestine into rumen

Paramphistomatidae *P. cervi and P. microbothroides

Distinguishing adult trematodes! Within the duodenum and rumen you find a super SMALL, rounded trematode with a posterior sucker. Whomst is it?

Paramphistomum

Trematode predilection sites in definitive hosts. Which trematodes go to the rumen?

Paramphistomum spp.

You do a fecal exam on a foal and notice round eggs with a dense, opaque, sticky protein coat. What is your top differential?

Parascaris equorum (Egg is characteristic of Ascarids. P. equorum is an Ascarid that infects foals and is shed in feces.)

2 species living together, where one is living at the expense of the other

Parasitism

type of host: They are not a necessary part of the life cycle. No parasitic development! Parasite sometimes can grow and should be transferable from host to host until they make its way into the final host

Paratenic Host

Under what circumstances is pathology of Ascaridia galli most severe? How can caretakers limit this?

Pathology is most severe in chickens (or turkeys) with poor nutrition and less so in well-fed animals with a robust immune response. Regular cleaning of feces in henhouses can help limit severe cases.

Pearsonema plica appears VERY similarly to Trichuris and Eucoleus (Capillaria). How are you able to distinguish P. plica from the others?

Pearsonema plica is located in the urine. You should NOT see it in feces with Trichuris and Eucoleus.

the increase in number of nematode eggs produced by ewes in the period 4 to 8 weeks after parturition

Periparturient Rise (PPR)

1 organism serves to carry the other one from place to place

Phoresis

Haemonchus worm burden correlates with ____

disease severity

Oesophagostomum dentatum causes ___ in pigs

enteritis

What is the predilection site for schistosomes?

Predilection site is the mesenteric veins/vessels.

What is the easiest way to identify Trichinella infection?

Presence of coiled larvae in striated muscle

____________ tapeworms have aquatic stages in their life cycles.

Pseudophyllidean

The digenean parasite family Paramphistomatidae are commonly known as ______________

RUMEN FLUKES

How do we treat dracunculus sp infection?

Removing the whole worm and caring for the wound in general. There is NO SPECIFIC DRUG OR VACCINE available

Source of infection for other animals

Reservoir

If the adult worm, onchocerca lupi, is located in the ___________ the case is usually asymptomatic

Retrobulbar space

what species do Trichostrongyles infect?

Ruminants, equines, swine

What three family of digenean parasites are most likely to infect definitive hosts by direct percutaneous infection by cercariae?

Schistosomatidae

Trematode predilection sites in definitive hosts. Which trematodes go to the circulation?

Schistosomes *mesenteric vessels

What causes Swimmer's Itch?

Schistosomes! Avian but sometimes mammalian. The cercariae penetrate the skin but die causing a delayed type hypersensitivity reaction (DTH)

What is the predilection site of Toxocara vitulorum? Who is the definitive host?

Small intestine of beef calves

Who are the definitive hosts for Parascaris equorum? What is its predilection site?

Small intestine of horses and donkeys

What is the predilection site of Ascarids? What do Ascarids eat?

Small intestine. Eat digested or partially digested food in the lumen of the gut.

How do you diagnose onchocerca sp?

Species identification of adult worm (morphologic or molecular). Microfilariae found in the dermis - skin snip biopsy

Commonly known as "Esophageal Worm". Parasite of the wall of the STOMACH or ESOPHAGUS of canids. May be found on the internal wall of the aorta though rare. Worldwide distribution but primarily in warmer regions (UNCOMMON IN US)

Spirocerca lupi

_____________ is a cestode in the order Pseudophyllidea. Has both an aquatic and terrestrial portion of its life cycle requiring a copepod and then terrestrial vertebrate (frogs, birds, snake, mammals) intermediate. Found more often in cats than dogs.

Spirometra mansonoides

___ should be suspected in outdoor raised pigs that do not gain weight normally

Stephanurus dentatus

The most destructive parasites of horses: strongylidae family

Strongylus vulgaris, Strongylus equinus, Strongylus edentatus

The only parasites in the trachea of domestic birds

Syngamus trachea (gapeworm)

____ infection in humans - stomach aches, abdominal bloating, and occasional diarrhea (eating strawberries from a garden fertilized with fresh sheep manure from infected animals)

TRICHOSTRONGYLES

Diagnosis of Habronema sp. and Draschia sp is done with gastroscopy to visualize the adult worms found in ____________ in the stomach. ________________ (fecal exam) can also be used.

TUMORLIKE MASSES; Fecal sedimentation! *Eggs are high density - not reliably detected by fecal flotation

What is the difference between the PPPs (pre-patent period) of Filaroides osleri and Filaroides hirthi? How is this clinically relevant?

The PPP of Filaroides osleri is 5-6 months. This is important because by the time the dog is showing clinical signs, there is already significant lung damage. The PPP of Filaroides hirthi is 32-35 days, much faster than F. osleri!

The drug of choice to treat Trichuris infection in dogs is fenbendazole. How should fenbendazole treatments be scheduled? How does this relate to the PPP (pre-patent period) of Trichuris?

The PPP of Trichuris is 3 months, meaning it takes 3 months for a hatched larva to mature into an egg-laying adult. Treatment should be administered once a month for 3 months. This ensures all different stages of parasite development are covered.

What comprises the infective stage of direct life cycles of Ascarids?

The egg (containing L2)

The two routes of vertical transmission of Toxocara canis are placental and transmammary. Which of the two causes the least amount of damage and why?

The transmammary route because it does not involve tracheal migration. No migration = no tissue damage. Larvae are directly swallowed by nursing pups and can easily reach the small intestine (predilection site), whereas in the placental route, arrested larvae in the livers of newborn pups become activated after birth and cause tissue damage as they undergo tracheal migration to ultimately get to the small intestine.

"Eye worms". Parasites of the of the conjunctival and lachrymal sacs of domestic and wild animals. They are WIDESPREAD across the world.

Thelazia sp.

What treatments are available for Filaroides sp. infections?

There are no drug recommendations currently. Treatment is difficult, but the best method is control and prevention (isolate positive dogs, C-sections, foster moms)

Ascarid that infects the small intestine of beef calves through transmammary transmission. Rare in North America due to tropical/subtropical distribution but has been observed in Northern Florida. ZOONOTIC!

Toxocara vitulorum

Treatment and prevention of Thelazia sp. infection

Treatment: 1) Cattle - DORAMECTIN and remove worm Prevention: limit access to IH

Treatment and prevention of spirocerca lupi.

Treatment: 1) Milbemycin oxime: 2) Doramectin every week Control and Prevention: 1) Moxidectin + imidacloprid (topical), Milbemycin oxime (oral) 2) Limit access to IH and PH *none of this was bolded

Treatment and prevention of onchocerca sp.

Treatment: SURGICAL REMOVAL of parasitic nodule Prevention: limit access to intermediate host

Name the two Trichinella species that are associated with current human cases of trichinosis believed to be from consumption of undercooked pork and bear meat.

Trichinella britovi, Trichinella murrelli

Trichinella sp. infections are not of significant concern in veterinary medicine. Why do we care?

Trichinella is very important for OneHealth and can occasionally cause serious disease humans. (ZOONOTIC!)

You're a human doctor, and your patient presents with muscle pain after eating raw meat. What is your top differential?

Trichinella sp. infection

This Trichinella species is of great concern because it does very well in domestic swine and humans. However, due to great success of clearing swine of infection worldwide, infection of this species is now very rare!

Trichinella spiralis

Genus of Nematodes that is commonly known as "whipworms" due to their whip-shaped bodies

Trichuris

Name the genus! - Found only in mammals - Anterior end is fine/hair-like and embeds into the large intestinal wall - Posterior end is stout and lies free in the lumen - Eggs are lemon-shaped with a distinct plug at each pole. They consist of a single cell when passed in feces.

Trichuris (whipworms)

(T/F) Acanthocephalans or the spiny headed worms have separate sexes, no gut, high reproductive output, and the males have cement glands.

True! Cement glands in males used to seal female vagina after copulation - sexual competition

(T/F) The intermediate host for Thelazia sp. are parasite specific.

True! It's DROSOPHOLID FLIES Different species of these flies are the host for the different Thelazia sp.

What are some possible interpretations of a ANTIGEN NEGATIVE and Microfilariae POSITIVE heartworm test?

UNEXPECTEDLY NEGATIVE antigen tests 1) Not a D. immitis microfilariae 2) Low worm burdens 3) Low antigenemia 4) Appearance of microfilariae prior antigenemia - RARE! 5) Presence of ANTIGEN-ANTIBODY complexes: Blocked antigen!

What are some of the limitations of serology testing (antibody and antigen tests) for heartworm in cats?

Unisex infections with only male worms or symptomatic immature infections go undetected *Antibody tests only detect mature adult female Ag

What clinical signs are most commonly seen with Filaroides hirthi?

Usually there are no clinical signs, but a focal granulomatous tissue reaction on the lung parenchyma can be seen. Fatal cases of hyperinfection have developed in severely stressed or immunodeficient animals.

Pathology that occurs from Ascarid infection in zoonotic hosts (humans!), when parasites undergo somatic migration in dead end hosts. Depending on the tissue, can be problematic.

VLM (visceral larva migrans)

which branch of vet parasitology? Arthropods (insects, ticks, mites)

Veterinary Entomology

which branch of vet parasitology? Helminths (trematodes, cestodes, and nematodes)

Veterinary Helminthology

which branch of vet parasitology? Single-celled eukaryotic organisms (protozoan)

Veterinary Protozoology

What is one way Toxocara canis transmammary infection be prevented?

Wean the puppies prior to the time it takes for T. canis to appear in the milk. (It takes T. canis ~7 weeks to be transmissible in milk. )

How can hypobiosis of Toxocara canis lead to organ damage?

When larvae first arrive to a tissue of an organ, they are active and produce secretions that elicit a host immune response to form granulomas. Eventually the larvae go dormant but remain in granulomas. This can lead to organ damage because normal tissue (ie in kidneys) that is being replaced by the granuloma is not functional.

Who is the most susceptible to Histomonas meleagridis?

Young turkeys (can reach 100% mortality!)

Disease of animals acquired from humans

ZOOANTHROPONOSIS

what is biotic potential?

ability of a pathogen to be successful (What is the maximal unrestricted growth of a population?Reproductive potential is a component of this.)

Haemonchus, Ostertagia, Trichostrongylus (HOT) plus Cooperia are the genera that infect the _____ and _____ of grazing ruminants.

abomasum, duodenum

The eggs of acanthocephalans such as macracanthorhynchus hirudinaceus can be distinguished based on their thick brown shell and the presence of fully-developed larva in egg known as __________

acanthor

Monogenea are mostly ectoparasites of ___________(animals). They are hermaphrodites with a ____________ lifecycle and as such are viviparous. They feed on the epidermis, blood, and mucus and pathogenesis is a function of parasite burden. Examples include ____________ spp.

aquatic animals; DIRECT; Gyrodactylus and Dactylogyrus spp *problematic for aquarium fish and aquaculture

Survival of many of these nematodes is associated with their ability to undergo _____

arrested development

Clinical signs and pathogenesis of Dirofilaria immitis is different in cats and dogs. Cats tend to usually be _________ harboring very few adult worms. When they do develop severe disease it is as a result of young adult worms migrating to the ________ causing ___________ disease.

asymptomatic; lungs; HARD: heartworm associated respiratory disease

Cestodes in the order Pseudophyllidea require ___________ intermediate hosts

at least two

why do Trichostrongyles need to make so many eggs?

because very few eggs survive to maturity

Platynosomum fastosum is a fluke of the ___________ in the family Dicrocoeliidae (infect definitive hosts through consumption of secondary intermediate hosts)

bile and pancreatic ducts of cats

Trichostrongyles have a high ____ meaning they can produce 500-2,000 eggs per day

biotic potential

Primary pathogenic mechanism in hookworm disease is ingestion of_____ by adult worms in the small intestine

blood

Schistosomatidae are known as ____________ flukes. One of the most significant schistosomes both of vet medicine, as it affects cattle, and of human medicine, as it is zoonotic, is _______________

blood; Schistisoma japonicum

Order Strongylida parasites are (bursate/non-bursate)

bursate

nematodes can be classified into two categories ____ and ___

bursate and non-bursate

Some clinical signs of dirofilaria immitis include exercise intolerance, arrhythmias, weight loss, ascites, coughing, congestive heart failure and ____________, a life threatening condition that occurs when worms present in the post cava/ right atrium interfere with the function of the tricuspid valve which can result in hemolytic anemia and right heart failure.

caval syndrome

Adult worms of Heterakis gallinarum reside in what part of the body of the definitive host?

cecum

Egrets and Lifestock animals: egrets eat insects kicked up by the cattle hooves as they move is an example of

commensalism

Sheep and goats are most severely affected by Haemonchus _____.

contortus

Paragonimus kellicotti is a ZOONOTIC lung fluke in the family Troglotrematidae. This family infects definitive hosts through consumption of a secondary intermediate hosts. What is N. salmincola's secondary intermediate host?

crustaceans

Ancylostoma caninum can infect people and cause ____

cutaneous larval migrans

what is the direct life cycle of a nematode?

definitive host ingests the organisms (types: free-living larvae, eggs hatch, eggs do not hatch)

The basic life cycle of Ascarids is (direct/indirect).

direct (Host eats infective egg. Transport/paratenic hosts may be used)

Hookworms transmitted by the oral route predominately go towards _____

direct GI development

Hookworms transmitted by the transmammary route predominately go towards _____

direct GI development

Which domestic animal is the most common definitive host for Dioctophyma renale?

dogs (occasionally: cats, pigs, cattle, horses, humans)

Dirofilaria immitis is probably the most important parasite of ______ in North America though it is found worldwide. Definitive hosts include: __________

dogs; Dogs, wild canids (coyotes), ferrets, others *cats not as good a host but show clinical disease

What are the two paratenic hosts of Ascaris suum?

earthworms and dung beetles (pig = definitive host)

PH of Syngamus trachea

earthworms, snails, slugs, and larvae of Musca domestica

in ruminants, hookworm pathogenesis leads to ___ due to blood loss

edema

Lifecycle of Strongylus edentatus: L4's migrate to ____ and molt to L5's in the _____

flanks, peritoneum

Trematodes are also known as _________

flukes

Trichostrongyles: Environmental conditions affect survival, but some can overwinter and survive as ___

free living worms

Main clinical sign of Stephanurus dentatus is failure to _____

gain weight

Ancylostoma caninum L3 in the skeletal muscle or gut wall is a diagnostic example of ______

hypobiosis

What does the clinical presentation and signs of Thelazia sp. infection depend on?

intensity of infection, length of infection prior to diagnosis, and host species

the ___ host provides physiological requirements for development of larvae and advantages for transmission of parasitic nematodes

intermediate

Nanophyetus salmincola is a ___________ fluke in the family Troglotrematidae (infect definitive hosts through consumption of secondary intermediate hosts)

intestinal fluke *eggs can be visualized on fecal float

infectious animal diseases are caused by _____

invasive self- replicating agents

Where is Physaloptera spp. located in the host?

may be found in anterior most portion of DUODENUM in dogs adult worms usually located in the stomach

Nematodes are ______ animals with multiple body systems. (Digestive •Reproductive •Nervous •Excretory)

metazoan

The unsheathed first-stage larvae of Dirofilaria immitis (and other members of the Filarioidea family). Can be detected about 5 - 6 months post infection. Determination of the length, width, and shape of the head should allow identification

microfilariae

At each stage in the nematode life cycle there is a ___, after which the nematodes increase in size

molt

Characteristics of Cyclophyllidae one of the main orders of cestodes. 1) They have four radial __________ on scolex which are used for attachment and locomotion. Most scolices also have a __________, a dome-shaped projection at apex of scolex, often retractable and armed with small hooks 2) Longer than wide segments

muscular suckers; rostellum

Ruminococcus and Selenomonas: These bacteria obtain nutrients from the ruminant's diet, and the animal gets energy from the products of bacterial metabolism is an example of ____

mutualism

Oesophagostomum spp. form ___ seen at necropsy disseminated in ruminants, concentrated in cecum and colon in pigs

nodules

ostertagia worms in the glands of the abomasum cause ___ scattered throughout the abomasum with worms sticking out

nodules

Cattle are most severally affected by Ostertagia ______.

ostertagi

_____ is the most important endoparasite of cattle worldwide. damage casued by the worm can result in lost productivity throughout the life of the animal

ostertagia

Paragonimus kellicotti is a ZOONOTIC lung fluke in the family Troglotrematidae. Adults are found in _________ in the lung. __________ disease occurs as a result of migration of this parasite in the lungs.

pairs; respiratory

Human botfly uses other flies as vehicle to save energy is an example of ____

phoresis

Ascaris suum is an Ascarid that infects what animal?

pigs (definitive host)

OSTERTAGIOSIS: Elevated _______ indicate extensive mucosal damage in the abomasum and reflects intensity of infection

plasma pepsinogen

Trematodes, cestodes, and tuberallarians are all in the phylum _______________ also known as flatworms as they are soft-bodies with a flattened appearance

platyhelminthes

What types of animals are infected by Ascaridia galli?

poultry (turkeys and chickens)

Dracunculus spp., physaloptera spp., habronema spp., draschia spp., thelazia spp., and spirocerca lupi are all within the superfamily _____________

spiruroidea *within suborder Spirurida

cythostomosis has a seasonal occurrence, causing diarrhea in the ___

spring

Trichostrongylus axei infects the ____ and causes erosion of the glandular epithelium, nodules, and hyperemic gastritis in horses

stomach

Habronema sp. and Draschia sp. are parasites of the ____________(location) of ________________(species).

stomach (near margo plicatus); horses and donkeys

Spirocerca lupi is a parasite of the ____________(location) of ________________(species). It is commonly known as ________.

stomach or esophagus; canids; Esophageal Worm *may also be found on internal wall of the aorta

Physaloptera sp. are parasites of the ____________(location) of ________________(species).

stomach; carnivores

Cestodes (tapeworms) are hermaphrodites. The adult worm is a chain (___________) of independent, progressively maturing reproductive units which eventually bud off in segments called __________. All stages of development are displayed in a linear array, from the ____________ which is the end anchored to the intestinal wall, to the distal end of the worm.

strobila; proglottids; scolex

____ is the diagnostic stage of hookworms and other members of strongylida

stronglye-type egg

Dracunculus sp. are parasites of the ____________(location) of ________________(species).

subcutaneous tissues; carnivores and humans

Stephanurus dentatus is a kidney worm in _____ (animal), found in peri-renal fat and walls of the kidney

swine

Animals that live in close association with each other are called_____ living together in the process of _______.

symbionts, symbiosis

Alaria spp are intestinal flukes in the family Diplostomatidae. This family infects definitive hosts through consumption of a secondary intermediate hosts. What is Alaria spp secondary intermediate host?

tadpoles!

A ZOONOTIC cestode in the family Taeniidae which causes cysticercosis and neurocysticercosis. Prevelant in many parts of SA, Africa, and Asia. Has a pig to human life cycle with dogs sometimes acting as incidental hosts.

taenia solium *also known as armed tapeworm and pork bladderworm *order cyclophyllidea

Cestodes are more commonly known as __________

tapeworms

How do cestodes (tapeworms) intake food?

they absorb it through their surface. no gut! absolutely bonkers!

(T/F) Tapeworms are very small worms

they do be long bois (typically less the 5 meters known to reach 25 m)

Digenea are _________ or ________ dwelling trematode endoparasites. Nearly all are hermaphrodites and eggs are found in feces, urine, sputum, or mucus. Common predilection sites for these parasites include: ____________

tissue or blood; bile and pancreatic ducts of liver, small intestine, rumen, lungs, circulatory system

Syngamus trachea is called a gapeworm, because the predilection site is the ___

trachea

Hookworms transmitted by the percutaneous route predominately go towards _____

tracheal migration

No ______ or prenatal infections with other hookworm species in dogs and cats, only ancylostoma caninum

transmammary

treatment for cythostomosis

treat with IVM, MOX, FBZ

Crenosoma vulpis is rare in North America (T/F).

true

Strongyloides spp. are not very problematic for animals but they are of importance because they can cause severe disease in humans (T/F).

true

T/F- Every host is vulnerable to infection by several (if not many) parasitic species.

true

T/F- LARVAL CYATHOSTOMOSIS can be unresponsive to some anthelmintics

true

T/F- Lactogenic transmission (transmammary) to pups does not involve tracheal migration

true

T/F- cythostomosis fecal eggs counts may be low since signs are causes by emerging larvae

true

Vertical transmission via placental or mammary glands is common in Ascarids (T/F).

true

T/F- Healthy, well-fed animals better able to compensate for chronic hookworm infection

true Malnourished or diseased animals less able to compensate

Monthly heartworm preventative is effective to prevent both Trichuris and Eucoleus infections (T/F).

true (Ivermectin is effective for both.)