VTA 130 Ectoparasites

Diagnostic techniques for ectoparasites

-combing/ seperating the hair- ear swabbing+microscope - skin scraping+microscope- acetate tape test+microscope

Rocky Mountain Spotted Fever (Rickettsiosis, Rickettsia)

A bacterial infection that causes fever, headache, muscle pain, and rash. (ONLY TRANSMITTED BY THE AMERICAN DOG TICK)

Mange mites

A skin and hair condition caused by 2 types of subcutaneous mites. One is contagious and the other is not.

Most common types of fleas

Ctenocephalides canis (dog preffered) and Ctenocephalides felis (cat preffered). Fleas are not host specific, they will attack other animals and humans. Common in warm, humid enviroments. (fleas are common intermediate hosts for cestodes (tapeworms)

What is exudate made of

Discharge from the body in response to inflammation or infection (ear gunk)

Tick Life Cycle

Eggs, Larva, Nymph, Adults (femals ticks when fully grown are the only ones to swell when feeding)

Biting Lice

Mallophaga

Tick Fever (Ehrlichiosis)

a bacterial infection transmitted via tick bite that causes thrombocytopenia, WBC disorders, bleeding disorders, splenomegaly. Once a tick takes up the bacteria via blood meal it will transfer the disease in the next blood meal. (ONLY BROWN DOG TICKS AND LONESTAR TICKS CARRY THIS DISEASE)

Zoonose refers to

a disease that is transmitted from animals to humans

Primary or Definitive Host is

a host in which the parasite reaches maturity and reproduces

Ectoparasite are

a parasite that infects the outside of the body

A Resevoir Host is

a primary host that harbors parasites asymptomatically (with no ill effects, signs, or symptoms)

A Secondary or Intermediate Host

harbors the parasite only for a short transition period., during which some developmental stages are complete.

A parasitic host

is a secondary host in which no parasite development occurs, but is still needed in order to complete the life cycle.

Host is

organism that harbors a parasite

How to remove and/or kill ticks

should be removed with head intact, leaving it behind can lead to innfection or disease transmission. Place in alcohol or squash to kill.

Demodex Mites

these are part of the normal skin flora or large animals. most hosts have a balanced relationship with the mite but when the animal is immune compromised and will then display signs of demodectic mange. (THIS FORM IS NOT CONTAGIOUS)

Facts about Lice

they live on the surface of the hosts skin and spread via direct contact. there are 2 main types of lice: biting/chewing lice and sucking lice- this can cause severe anemia- (INFESTATION OF ANY TYPE OF LICE IS CALLED PEDICULOSIS)

Tick facts

ticks on domesticated animals are not host specific but do have preferences.

How do you skin scrape

use a #10 scalpel blade, hold the blade perpendicular to the skin at the outer edge of a lesion and scrape until blood or bleeding tissue is present. hair, skin cells, and blood will be collected. place on a slide with mineral oil and view. cover with a cover slip. the objective used depends on the mite in question. (typically the lowest 2 objectives suffice.)

What is the Acetate tape test

use special tape, cellaphane or clear scoth tape. Place a tape over suspicious areas sticky surface down. place the tape on a slide and view under the microscope. A stain may be used (methylene blue)

Parasites that carry and transmit infectious diseases are called what

vectors. ticks are common vectors of disease. also mosquitos

Tularemia (rabbit fever)

American dog ticks are vectors of this bacterial disease, they transmit it to rabbits and humans. (THIS IS A ZOONOTIC DISEASE CARRIED BY RABBITS) Humans can contract this by a bite from an infected tick, horsefly, or mosquito. Breathing infected dirt or plant material. Direct contact through a break in the skin with an infected or dead animal. Or ingested infected meat.

Incidental or Dead-End Host

An accidental host which serves no benefit to the parasite because it cannot be transmitted back to the definitive host from here. (humans are considered dead-end hosts for echinococcus - canine tape worm- because it wwould require the infected human to be consumed to complete its life cycle.

Sucking Lice

Anoplura

Sarcoptic Mange Mite (Scabies)

This is a VERY contagious form of mange. humans can contract this form though it is short lived. humans are dead end hosts for scabies. Scabies is crusty, and extremely itchy compared to demodex mange.

Common tick-borne diseases

Tick fever, Lyme disease, Rocky mountain spotted fever, Tularemia

Parasites are

an organism that lives on or inside another organism and causes it harm or inconvenience

Cheyletiella (walking dandruff)

causes severe flaking of the epidermis

Flea facts

eggs are layed into the fur to stay or fall into the ennviroment. Larvae hatch and feed on organic debris and dried blood. Flea dirt is dried blood left behind by feeding fleas.

Facts about Mites

most mites are host specific. They will not infect other species. in humans they infect for a little then die off. They live on their host and only infest other animals by chance. Treatments range from topical pesticides, ivermectin injections, shampoos, to dips.

Where do ectoparasites reside

on the skin surface or imbedded into the subcutaneous tissue. They can be visible to the naked eye or small enough to require microscopic examination.