FeLV

Question 1

What group does this belong to?

Answer 1

Gammaretrovirus

Question 2

What are the classic genes for retrovirus?

Answer 2

Pol (polymerase), env (envelope), gag (group antigen)

Question 3

How prevalent is it?

Answer 3

Worldwide, for cats <16 weeks of age. Outcome by host factors and viral strains

Question 4

How is it transmitted

Answer 4

Saliva through bites or mutual grooming, urine, feces, mother to kitten

Question 5

Where does it replicate and what are the associated signs?

Answer 5

Lymphoid tissue-either local or systemic, associated viremia, replicates in bone marrow and the original viremia starts with PMNs and platelets there

Question 6

What are the stages of infection?

Answer 6

Localized (rare), abortive infection, persistent viremia leading to progressive infection (30% cats), Regressive viremia leading to latent infections and stress or immunosuppression leads to progressive.

Question 7

What is progressive infection?

Answer 7

Persistent replication in the lymphoid tissues leading to viremia, ineffective anti-viral host response.

Question 8

What is regressive infection?

Answer 8

Virus replication is contained and have low levels in blood, present in bone marrow, some cats reactivate infection

Question 9

What is the pathogenesis of FeLV?

Answer 9

either degenerative (non neoplastic) or neoplastic/proliferative disease

Question 10

Explain degenerative disease

Answer 10

Affects lymphoid cells and see a loss of T and B cells, induces immunosuppression and secondary infection. Half of cats with FIP/chronic disease used to be FeLV positive. Can see thymic atrophy in kittes

Question 11

What are some of the sequelae of degenerative disease?

Answer 11

Can see immune complexes in the kidney (glomerulonephritis), anemia, thrombocytopenia. Myelodegenerative

Question 12

Explain proliferaitve disease

Answer 12

Have higher chance to develop lymphoma or leukemia

Question 13

What are the three major types of carcinogen?

Answer 13

Chemical mutagens, physical carcinogenesis (like radiation) and infectious pathogens or viral

Question 14

What are viral oncogenes?

Answer 14

In the virus; can produce malignant transformations

Question 15

What are protooncogenes?

Answer 15

In the host, can be growth factors, protein kinases, etc. Cellular genes involved in growth and development

Question 16

What are the oncogenic mechanisms by the virus?

Answer 16

Direct-insert oncogenes or transform already existing protooncogenes in host. Indirect-chronic nonspecific inflammation or disruption of tumor surveillance (like tumor suppressor genes). FeLV DOES NOT have its own viral genes so instead inserts itself near host protooncogenes

Question 17

What are the forms of lymphoma?

Answer 17

Thymic or mediatsinal, alimentary, multicentric, atypical

Question 18

What is thymic lymphoma?

Answer 18

Cats about 2 years old, displaces heart dorsocaudally, can see thoracic effusion, mostly T cell

Question 19

What is alimentary lymphoma?

Answer 19

in intestines, in middle aged or older cats, clinical signs related to intestinal or renal dysfunction and is usually a B or T cell phenotype

Question 20

What is multicentric lymphoma?

Answer 20

cats of wide age range, clinical signs based on organs affected and lymph nodes, mostly T cell based

Question 21

What is atypical lymphoma?

Answer 21

Located in small clumps in organs, if in brain can see neuro signs

Question 22

What percentage of cats with each type of lymphoma are FeLV+?

Answer 22

90% thymic, 66% multicentric, 33% alimentary

Question 23

What is FeLV induced leukemia?

Answer 23

lymphoblastic or megakaryocytic is most common. It is the neoplastic or proliferative form

Question 24

Which subtype is 100% prevalent?

Answer 24

A, can see in kidney, liver, T cells, small intestines. Only one that can be transmitted between cats.

Question 25

What if a cat is infected with subtype A and B?

Answer 25

Persistently viremic and have FeLV associated diseases

Question 26

Give a brief synopsis of Feline Sarcoma Virus

Answer 26

from combo of FeLv and host protooncogenes. Associated with multicentric fibrosarcoma

Question 27

What is the prognosis of FeLV?

Answer 27

85% with persistent infections die within three and a half years whereas uninfected cats die within 5-6 years once diagnosed. Most die from immunosuppression and secondary infections can be treated.

Question 28

How do you stop FeLV?

Answer 28

Reduce stress and identify persistently infected cats in order to make diagnosis or prognosis, have to do by testing

Question 29

How do you test and treat FeLV?

Answer 29

detect persistently infected cats by detecting the virus antigen via ELISA (gag), detect virus itself by IFA, detect genome by PCR. If doing serology, will identify virus neutralizing antibody (env). SNAP tests are for gag in blood. Most cats positive within 1 month of exposure, confirm FeLV by using different test (usually IFA).

Question 30

What is important for serology?

Answer 30

Remembering that cats that have been vaccinated against FeLV have antibodies! As will exposed and non-progressively infected cats

Question 31

The stages of FeLV-which will be positive for the tests?

Answer 31

Progressive will be positive for all tests, regressive is only totally positive for proviral DNA in the blood and most other tests are either negative or transiently positive. Abortive is not positive on any test and focal is only positive on viral tissue culture.

Question 32

How do you test for FeLV?

Answer 32

Have to test all cats entering shelters, test after 2 months again if negative, at risk cats, cats with households with FeLV, cats BEFORE VACCINATION. Blood donor cats tested for FeLV antigen and provirus.

Question 33

How do you prevent and control FeLV?

Answer 33

Vaccinate, testing and eliminating, sanitization with diluted bleach, keep FeLV-infected cats indoors, do testing for asymptomatic cats with infection, treat secondary infections.

Question 34

What is the FeLV vaccine?

Answer 34

not a core vaccine but recommended for kittens up to 1 year of age, booster only for cats with high risk of exposure (outdoor, indoor-outdoor, stray, feral, FeLV-positive households). Three killed vaccines and one recomb. Vaccine decreases transient and persistent viremia, latent infections, risk of FeLV secondary diseases.