Feline Leukemia

What happens when an FeLV patient is in latency level?

-Cat encounters virus from infected cat, harbors virus, and isn't detectable with normal in-house testing. -Virus can remain undetected for an average of 2 years. During this time the cat appears normal.

What happens when an FeLV patient becomes an Immune Carrier?

-FeLV hidden in some epithelial cells -Although FeLV is multiplying, not able to get out of cells because cat is producing antibodies against it. -Cat appears normal in every way -Represents 1-2% of cases. -Will die at about 8-10 years of age.

How is immunity for FeLV obtained by prevention and control?

-Ideally- prevent multi cat contacts -If multi-cat household exists, separate FeLV positive and negative cats -Vaccinate with subsequent testing of FeLV

What client information can be given to prevent FeLV for their cats?

-Limit or eliminate all contact with other cats, but maybe not always possible or practical. -Best solution is to test and vaccinate and re-vaccinate yearly when seeing the vet.

What happens when an FeLV patient has secondary viremia?

-The diseases is characterized by a persistent infection of bone marrow and soft tissue. -Cats infected at this level will be infected forever (30% of Cats) -Ultimately cat will die after demonstrating symptoms of primary viremia for a few days and recover for up to 3 years only to be stressed, relapse, and die.

What are the four possible outcomes of an FeLV infection?

1.) They will have primary viremia 2.) Have secondary viremia 3.) Have Latency 4.) Be an immune carrier

What four things are categorized under non-neoplastic diseases related to FeLV?

1.) Thrombocytopenia 2.) IMHA (Immune-Mediated Hemolytic Anemias or lupus) 3.) Glomerulonephritis 4.) Thymic atrophy (fading kitten syndrome)

What was the range in tumor incidents due to the vaccine?

1/1000- 1/10,000 vaccines

When was Feline leukemia identified?

1964

Studies show significant protection for how long post subunit vaccine following initial series?

2 years

What percentage of cats born infected by FeLV InUtero survive birth and continue being infected for life?

20%

What percentage of the cats latent with FeLV are infected persistently? What percentage of cats latent with FeLV, infected persistently die within 3 years?

30% (83% die within 3 years)

What percentage of cats become latent with FeLV- (neither fully or seriously ill)?

30% (stress will kill in the future)

What percentage of cats develop an immunity to FeLV?

40%

How many stages of pathogenesis are involved in FeLV?

5

What percentage of FeLV positive cats have both FeLV A and FeLV B subgroups?

50%

___-_____% of neonatal kittens infected vs only ___-___% of the kittens older than 8 weeks and less than ____% of adolescent and adult cats develop persistent viremia.

70-100% 30-50% 30%

What percentage of FeLV positive cats have FeLV A?

90% - is by far the most common

What two things does FOCMA antigens that produce antibodies allow to happen to the patient?

Allow for the diagnosis of FeLV infection Despite diagnosis causes an inevitable progression and disease.

What has been shown to be effective for protective activity against neoplasias due to FOCMA, but NOT FeLV induced non-neoplastic diseases?

Antibiotics

________ have good/some protective activity against FeLV neoplasms.

Antibiotics

What two areas does a secondary viremia of FeLV continue a persistent infection?

Bone Marrow and soft tissue

What is the only way to get FeLV B, FeLV C, FeLV-myc and FSV?

By recombination of FeLV genes

What is usually causes a traditional leukemia?

Cancer of the white blood cells

How is the outcome of pathogenicity of FeLV in an infected cat determined? (3)

Depends on- Age, Immune status, and Agent Factors (virulence, dosage, route of inoculation)

As far as prevalence, FeLV infections exist in __________ ______ _________. FeLV is __-___% in free roaming cats world wide.

Domestic cats worldwide 1-8%

Who identified Feline leukemia as a suspected etiological agent of lymphosarcomas?

Dr. Jarrett

What are the three diagnostic tests for FIV?

ELISA test, IFA test, and Immunoblot or western blot test

What are the three diagnostic tests for FeLV?

ELISA test, IFA test, and viral isolation

What are symptoms of FeLV subgroup B?

Either severe myeloproliferation or myelosuppresion Immunosuppresive and neoplastic disease conditions

Where are non-domestic felids (wild cats) with FeLV found to be enzootic? Can other wild cats be susceptible to FeLV?

European wild cats in France and Scotland Yes

Neo-Plastic diseases related to FeLV are virtually identical to disease conditions of ____.

FIV

True or False: Reverse transcriptase of FeLV with its genome organization is more complex than FIV

False, FIV is more complex

True or False: Other subgroups of FeLV besides FeLV A are infectious.

False, only FeLV A is infectious but the other subgroups can be generated by a mutation in an FeLV A cat.

What is Feline Leukemia classified as (family, subfamily)?

Family Retroviridae Subfamily Oncornavirinae

Of all the FeLV divided subgroups which one is the ONLY one that is infectious and transmitted from cat to cat?

FeLV A

What is the most common subgroup of FeLV?

FeLV A

What are the different subgroups for FeLV?

FeLV A FeLV B FeLV C FeLV-mye

What two subgroups of FeLV are often present as a co-infection?

FeLV A and FeLV B

Why do we vaccinate for FeLV A and not other subgroups of FeLV?

FeLV A is more deadly because it has a rapid viremia for infection.

What subgroup is a persistent virus seen in young kittens?

FeLV C Kittens are aborted when born with persistent aplastic anemia and usually die.

What two vaccines caused fibrosarcomas most commonly? What adjuvants of those vaccines were responsible?

FeLV and Feline Rabies vaccine Aluminum

Between both ELISA tests for FIV and FeLV, which ELISA test is a better test for which virus?

FeLV has a better ELISA test

What was the 1964 etiology for Feline Leukemia Virus?

FeLV-27

What is the most common cause of cancer in cats?

Feline Leukemia

What does FOCMA stand for?

Feline Oncornavirus- Associated Cell Membrane Antigen

_______ _______ ______ is a mutation of genes of FeLV and its host cells.

Feline Sarcoma Virus

Which virus is not a subgroup of FeLV but is a recombination of FeLV A genome with cancer-associated cellular genes and generated in FeLV A positive cats?

Feline Sarcoma Virus (FeSV)

What are the possible results of InUtero infections of FeLV?

Fetal resorption, abortion, neonatal death, and sometimes they survive InUtero infection, but remain infected for life.

What is the most frequently occurring type of soft tissue sarcoma?

Fibrosarcoma

What were 2 viruses originally identified as associated with FeLV?

For Tumors = Feline Sarcoma Virus For identification = Feline Oncornavirus- Associated cell Membrane Antigen (FOCMA)

How was the initial spread of FeLV inhibited by cats?

From the arid nature of North Africa

What two types of vaccines are available for FeLV?

Inactivated whole virus vaccine Inactivated sub-unit vaccine

What can be attributed to the development of age-related resistance?

Increasing immunocompetence of cats.

What happens in Stage 2 of FeLV?

Infection of circulating lymphocytes (B cell lymphs)

What happens in Stage 5 of FeLV?

Infection of epithelial and glandular tissue shedding virus in saliva and urine.

Who created the 1st FeLV vaccine and what was it called?

Leukocell by Norden

What are the two neoplastic diseases associated with FeLV? Which one is most common?

Lymphoma (lymphosarcoma) - solid tumors- This is the most common neoplastic disease Lymphoid leukemias - non-solid tumor

What kind of cats does FeLV affect?

Mainly domestic cats, but there are few cases of non-domestic cats

What two types of diseases can be associated with FeLV?

Neoplastic diseases and non-neoplastic diseases

What caused the induction of tumors associated with FeLV?

Protein on the cells of Feline Sarcoma Virus and Feline Leukemia

It was determined that FeLV evolved from an ancestor in what animal?

Rats

What happens in Stage 4 of FeLV?

Release of infected neutrophils and thrombocytes from bone marrow

What happens in Stage 3 of FeLV?

Replication in spleen, intestinal lymph nodes (Peyer's patches), and marrow

Feline leukemia produces an enzyme called ________ _________ that permits it to insert copies of its own genetic material into infected cells.

Reverse transcriptase

Does saliva or plasma have more concentration of FeLV?

Saliva

What happens when an FeLV patient has primary viremia?

The immunity is built by the host (Also caused by vaccine) -Host amounts immune response and flushes infection from blood but takes a few days to complete. -Host may become lethargic with anorexia. -Symptoms last 3-10 days -Occurs in about 40% of the cases when cats are challenged for the first time.

Why are commercial tests used for viral antigens and not antibodies?

The previous vaccination may interfere with test and give false positive.

How does FeLV spread?

Through close contact between virus shedding cats and susceptible cats. Primarily by saliva.

What are the 3 classifications of lymphomasarcomas (solid tumors)?

Thymic (mediastinal lymph node), Multicentric (all four sets of lymph nodes effected), and alimentary (Peyer's patches)

After initial infection, virus replicated in _______ and _________ _____ ________ and then spreads via blood stream.

Tonsils Pharyngeal lymph nodes

What in more specific ways can cats transmit FeLV vertically?

Transplacentally or when groomed by mother

True or False: The concentration of FeLV virus in blood/saliva can be found equally in an asymptomatic cat as a symptomatic cat.

True

How is FeLV transmitted (2)? What bodily fluids have a concentration of FeLV that can be transmitted? (4) What are possible ways it can happen? (3)

Vertically between mother and kittens or horizontally among communal cats that have prolonged close contact. Social behavior is the biggest reason horizontal transmission is possible. -saliva, urine, epiphora, and milk -Sharing food/water -Mutual grooming -Sharing litter boxes

How did FeLV eventually affect cats from rats?

Via ingestion or bite from rat

What happens in Stage 1 of FeLV?

Viral replication in tonsils/regional lymph nodes

The term _______ is used loosely to include all diseases associated with the virus, even though most are not cancer of the blood.

leukopenia

Lymphoid leukemia usually develops with ____-______ form of lymphoma, but occasionally only involves ______ and _____ _______. These non-solid tumors have increased in number of lymphocytes of _______ ______.

multi-centric Blood and bone marrow Immature nature

FOCMA can be described as a ______ _______ - found on cell membranes of ______ and ______ tumors.

protein antigen FeLV, FeSV