Feline Retroviruses Flashcards
What is the viral core protein produced by infected cells that are detected by FeLV antigen tests?
p27
Which cats are most susceptible to FeLV?
Young kittens
- Others include those in a high population density & outdoor cats
How is FeLV transmitted?
Horizontal transmission - saliva, nasal secretions, milk, urine, feces (close contact, bites)
Vertical transmission - in utero, nursing
Describe the pathogenesis FeLV infection.
Typically acquired through oronasal exposure -> viral replication in local lymphoid tissues of oropharynx -> monocytes & lymphocytes infected -> goes to circulation -> primary viremia (lasting 3-6 weeks) -> viral replication in bone marrow -> secondary viremia that is associated with progressive infection
When is FeLV detectable by IFA?
30 days after exposure
What are the 3 possible outcomes of exposure to FeLV?
- Progressive infection
- Regressive infection
- Abortive infection
Which outcome of exposure to FeLV is associated with persistent viremia & shorter survival time?
Progressive infection
T/F: There are low to undetectable levels of neutralizing antibodies in cats with progressive infection of FeLV.
T
With progressive infection of FeLV, state if the test would be positive or negative:
POC FeLV test, PCR, & IFA
POC FeLV - positive (unless very early infection)
PCR - positive & in high numbers
IFA - ONLY POSITIVE W/ PROGRESSIVE (indicates bone marrow involvement)
Which outcome of exposure to FeLV is associated with transient viremia?
Regressive infection
Which outcome of exposure to FeLV does not lead to viremia?
Abortive infection
With regressive infection of FeLV, state if the test would be positive or negative:
POC FeLV test, PCR, & IFA
POC FeLV - can be positive in first 16 weeks of infection
PCR - can be positive OR negative (if positive should be lower in #s)
IFA - negative!
T/F: Abortive infection associated with FeLV does not develop viremia, and therefore won’t have any detectable antibodies.
F - do have detectable antibodies
With abortive progression of FeLV, state if the following tests will be positive or negative:
POC FeLV test, PCR, & IFA
POC FeLV - negative
PCR - negative
IFA - negative (duh)
What is the most common hematologic abnormality you will find on CBC of a cat with FeLV?
Macrocytic, non-regenerative anemia (sometimes pancytopenia)
What are the most common neoplasias associated with FeLV?
Lymphoma & leukemia
T/F: FeLV antigen test negative in most cats with lymphoma
T
In regards to FeLV associated lymphoma, mediastinal/alimentary (choose one) is associated with positive FeLV status, whereas mediastinal/alimentary (choose one) is not associated with it.
Mediastinal, alimentary
An ELISA FeLV/FIV antigen test will appear positive within how long of infection?
Within 4 weeks
You receive a positive FeLV ELISA SNAP test. What should you do next?
Repeat the ELISA (either in house or send it out to confirm)
T/F: Regressive cats may be positive on ELISA during transient viremia but should be negative within 16 weeks of infection.
T
What does a positive FeLV ELISA test mean?
It is either progressive or regressive infection
A cat is positive for FeLV on ELISA but had a negative IFA. What is your interpretation?
- Transient viremia (regressive infection)
- Early, before bone marrow infection in progressive infection
- Low level cell associated viremia (cytopenia)
- False positive (rare)
How do you treat a cat with FeLV?
You don’t
You can only treat the associated diseases
T/F: FeLV vaccination does not cause + FeLV test, but FIV vaccination does cause + FIV test.
T
Which cats are at greatest risk for FIV?
Male, outdoor cats
How is FIV transmitted?
- BITE WOUNDS
- Possible transplacental/nursing but uncommon
Uncommon in cats living together without fighting
T/F: Neoplasia is 5x more common in cats with FIV.
T
What are the clinical signs associated with FIV?
- Transient/mild or inapparent in initial stage
- Some may have no clinical signs at all
- Chronic infections get immunosuppression (recurrent infections, stomatitis)
What laboratory findings do you expect to see in a cat with FIV?
CBC - neutropenia, lymphopenia, anemia
Chemistry - hyperglobulinemia
Does the ELISA SNAP test look for antigen or antibodies to FIV?
Antibodies
What antibody tests can we use to detect FIV?
ELISA or Western blot (gold standard for FIV antibodies)
You run an FeLV/FIV test on a cat & it shows up positive for FIV. What is your interpretation?
- Truly infected (most cases)
- Vaccination
- False positive
- Maternal antibodies (up to 6mo of age)
If you run an FeLV/FIV test and it shows up negative for FIV but you are still suspicious, what are you going to do?
Could consider western blot test and/or retest no sooner than 60 days
An 8-week old kitten presents to you for a first visit. No previous history. What do you recommend in terms of FeLV/FIV testing & vaccination?
Recommend all kittens be tested for FeLV/FIV & vaccinated for FeLV no matter what lifestyle they have
