Feline Leukemia Virus (FeLV) Flashcards
What type of virus causes FeLV?
RNA retrovirus (oncornavirus- cancer causing)
T or F. FeLV is the most pathogenic retrovirus in cats.
True, most cats with viremia will eventually die
What geographical distribution does FeLV have?
Worldwide
Who is the poster child for FeLV?
Outdoor (feral), male cats, 1-6 years old
How is FeLV transmitted?
Vertical & saliva/ nasal secretions (prolonged contact, especially grooming and same water source)
What are the 3 types of post-exposure infections?
- Abortive infection ( aka transient viremia, 1st viremia, 30%)
- Regressive infection (40%)
- Progressive infection (aka persistent viremia, 2nd viremia, 30%)
Which type of infection develops neutralizing antibodies and clears the infection in 4-6 weeks?
Abortive infection (transient viremia)- test for antigen, so if + you have virus
Which type of infection usually results in death at 2-3 years?
Progressive infection (persistent viremia)
Where does the virus go during regressive infection?
Bone marrow, spleen, and liver > into cell > provirus into cat’s genome/ DNA
No viremia, no transmission, no replication (hard to diagnose at this stage)
Rare to cause clinical signs
How can FeLV cause cancer?
If the virus can get close to a regulatory gene during regressive infection
How long does it take to clear the abortive infection compared to the regressive infection?
4-6 weeks (abortive) vs. 16 months (regressive)
What signs will you see with FeLV?
Non specific signs (problems making cells), secondary infections (immunosuppressive; cutaneous abscesses, oral inflammation), neoplasia (lymphoma, leukemia), V/D, icterus, rhinitis, pneumonia
Also glomerulonephritis, ocular signs, and neurologic abnormalities
What will you see in the lab work for FeLV?
Non-regenerative anemia (macrocytosis), thrombocytopenia, neutropenia, lymphopenia
Also, myelodysplasia or leukemia, proteinuria
Who are you going to test?
Sick cats, cats before adoption, and cats with known exposure (after 28 days)
At least once in the cat’s life
How are you going to diagnose FeLV?
ELISA (+ in abortive and progressive infection) and IFA (+ only after bone marrow infection, contagious)
What type of infection do you have if ELISA is + and IFA is -?
Abortive infection
What type of infection do you have if ELISA is + and IFA is +?
Progressive infection
What do you do if ELISA tests positive?
Isolate and retest in 4-6 weeks (because we’re not sure if they’re going to get 2nd viremia)
How do you prevent FeLV?
- House cats indoors
- Test and separate seropositive cats
- Vaccinate negative cats (kittens and cats at sustained risk)
- Avoid sharing litter boxes and water bowls
- Test new cats
- Flea control (fleas can carry virus from one cat to another)
- Disinfect and wash hands at the vet
- PE every 6 months (CBC)
- Spay and neuter
What do you do in a positive cattery?
Test all cats (separate + and -)
However, neutralizing antibodies do not last for life; cats that were immune may get viremia
How do you treat FeLV?
Always treat secondary diseases, chemotherapy (somewhat responds), and alpha-interferon (immunomodulatory effect; SQ then PO)
How do you treat the hematologic disorders that come with FeLV?
- IMA
- Haemoplasmosis
- Myelosuppression
- Myeloproliferative disease
- Myelophthisis
- Leukemia
- Neutropenia
- Thrombocytopenia
- Thrombocytosis
Regenerative anemia
- IMHA: immunosuppressives (Pred)
- Haemoplasmosis: Doxycycline
Non-regenerative anemia
- Myelosuppression
- Pancytopenia: poor response to therapy
- Pure red cell aplasia: immunosuppressives (cyclosporine)
- Myeloproliferative disease:
- Erythroleukemia, anemia with macrocytosis: poor response to therapy
- Myelophthisis
- Lymphoma, CLL, granulocytic leukemia: cytotoxic chemotherapy
Leukemia: poor response to chemotherapy
Neutropenia: glucocorticoids
Thrombocytopenia: glucocorticoids
Thrombocytosis: poor response to chemotherapy (just an abnormal finding)
