FeLV Flashcards
What group does this belong to?
Gammaretrovirus
What are the classic genes for retrovirus?
Pol (polymerase), env (envelope), gag (group antigen)
How prevalent is it?
Worldwide, for cats <16 weeks of age. Outcome by host factors and viral strains
How is it transmitted
Saliva through bites or mutual grooming, urine, feces, mother to kitten
Where does it replicate and what are the associated signs?
Lymphoid tissue-either local or systemic, associated viremia, replicates in bone marrow and the original viremia starts with PMNs and platelets there
What are the stages of infection?
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.
What is progressive infection?
Persistent replication in the lymphoid tissues leading to viremia, ineffective anti-viral host response.
What is regressive infection?
Virus replication is contained and have low levels in blood, present in bone marrow, some cats reactivate infection
What is the pathogenesis of FeLV?
either degenerative (non neoplastic) or neoplastic/proliferative disease
Explain degenerative disease
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
What are some of the sequelae of degenerative disease?
Can see immune complexes in the kidney (glomerulonephritis), anemia, thrombocytopenia. Myelodegenerative
Explain proliferaitve disease
Have higher chance to develop lymphoma or leukemia
What are the three major types of carcinogen?
Chemical mutagens, physical carcinogenesis (like radiation) and infectious pathogens or viral
What are viral oncogenes?
In the virus; can produce malignant transformations
What are protooncogenes?
In the host, can be growth factors, protein kinases, etc. Cellular genes involved in growth and development
What are the oncogenic mechanisms by the virus?
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
What are the forms of lymphoma?
Thymic or mediatsinal, alimentary, multicentric, atypical
What is thymic lymphoma?
Cats about 2 years old, displaces heart dorsocaudally, can see thoracic effusion, mostly T cell
What is alimentary lymphoma?
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
What is multicentric lymphoma?
cats of wide age range, clinical signs based on organs affected and lymph nodes, mostly T cell based
What is atypical lymphoma?
Located in small clumps in organs, if in brain can see neuro signs
What percentage of cats with each type of lymphoma are FeLV+?
90% thymic, 66% multicentric, 33% alimentary
What is FeLV induced leukemia?
lymphoblastic or megakaryocytic is most common. It is the neoplastic or proliferative form
Which subtype is 100% prevalent?
A, can see in kidney, liver, T cells, small intestines. Only one that can be transmitted between cats.
What if a cat is infected with subtype A and B?
Persistently viremic and have FeLV associated diseases
Give a brief synopsis of Feline Sarcoma Virus
from combo of FeLv and host protooncogenes. Associated with multicentric fibrosarcoma
What is the prognosis of FeLV?
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.
How do you stop FeLV?
Reduce stress and identify persistently infected cats in order to make diagnosis or prognosis, have to do by testing
How do you test and treat FeLV?
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).
What is important for serology?
Remembering that cats that have been vaccinated against FeLV have antibodies! As will exposed and non-progressively infected cats
The stages of FeLV-which will be positive for the tests?
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.
How do you test for FeLV?
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.
How do you prevent and control FeLV?
Vaccinate, testing and eliminating, sanitization with diluted bleach, keep FeLV-infected cats indoors, do testing for asymptomatic cats with infection, treat secondary infections.
What is the FeLV vaccine?
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.
