FIV, RV, FeLV Flashcards
Prevalence of FIV
worldwide
correlates with size of feral, free roaming cat population
What is FIV nicknamed? Why?
“Mean Cat Dz”
Primary mode of transmission is through bite wounds
How is FIV spread?
- Saliva
- Semen (not as much)
- NOT via fomites b/c FIV is a weak virus
Signalment of an at risk individual for FIV
outdoor, free-roaming intact male cat
What cells types does FIV attack? Of those, which is the “favorite”?
- Favorite –> Lymphocytes (specifically the CD4+ Helper T-Cells, although it attacks CD8+ too)
- macrophages
- megakaryocytes
- certain bone marrow cells
What does FIV do to the lymphocyte? What does that result in and why?
- destroys it
- CD4+ maintain and mediate humoral and cell-mediated immune response, so decreasing the number of these cells diminishes the function of the immune system which makes the host less able to respond to inflammation and other antigens with the appropriate cells and the inflammatory mediators that those cells would produce.
- Result: immunodeficient state
Which cells can serve as a reservoir for FIV?
macrophages
megakaryocytes
List the 5 different stages of FIV
- Acute infection
- Asymptomatic carrier
- Persistent Generalized Lymphadenopathy (PGL)
- Not well defined
- Clinical immunodeficiency
Stage 1: Acute infection
- occurs when
- lasts how long
- clinical signs
Occurs appx 4 weeks post infection, lasting up to 4 months
CS: asymptomatic, lymphadenopathy (swelling of LN), neutropenia (low # neutrophils), pyrexia (fever), diarrhea
Stage 2: Asymptomatic carrier
- lasts
- clinical signs
- lasts many months to year (avg 7yrs)
- CS = none
Stage 3: Persistent Generalized Lymphadenopathy (PGL)
- lasts how long
- clinical signs
- duration is short; 2-4 months; may be missed by O and DVM
- CS: enlarged and firm LN that may or may not be painful
Stage 4 is represented by…
chronic respiratory, GI, and dermal infections
Stage 5: Clinical Immunodeficiency is represented by…
evidence of opportunistic infections, generalized emaciation, and/or lymphopenia (specifically of CD4+ T-cells)
Does FIV cause dz?
No. It just makes it easier for infections to occur
What are some common Dz found in FIV positive cats?
- Gingivitis, ulcerative or proliferative stomatitis and periodontitis
- Recurrent bouts of dermatitis and otitis
- Chorionic upper respiratory signs (coughing, sneezing, nasal/ocular discharge) that reoccur
- Anemia, lymphopenia, neutropenia, hypergammaglobulinemia
- Nerve disorders such as anisocoria, delayed PLR, paresis, altered behavior patterns
Methods for identifying FIV virus
- usually via identification of FIV-specific virus-neutralizing antibodies present in plasma or serum
- ELISA-based in-house tests
- IFA or Western Blot techniques used at outside labs for confirmatory testing
What type of tests has a higher chance of false positives and false negatives for FIV?
ELISA
What are 3 ways to nurse a sick, FIV+ cat?
- Stopping the virus with antivirals
- Boosting the response of the immune system via immunomodulation
- Managing the secondary, often opportunistic infections and maintaining hydration & nutrition
What FIV antiviral is out there? What does it do, and what are the side effects?
AZT –> inhibits the reverse transcriptase enzyme
Side Effects: some animals are resistant to it, high risk for anemia and other cytopenias, hepatotoxicity
What is the risk with immunomodulation therapy in FIV+ cats?
The therapy may also enhance production of the virus.
Can you vaccinate an FIV+ cat?
Yes. It won’t hurt the cat, but there’s a chance it won’t protect the cat like it should either.
How to prevent FIV?
- eliminate exposure to FIV+ cats
- keep cat inside
- FIV antibody screen prior to introduction of a new cat into an FIV- household
Is FIV zoonotic?
No, but it may make it more likely that the cat will harbor a Dz that is zoonotic
Who/What can get rabies? What species are most susceptible? What species are the primary source of human infection?
General: any warm-blooded animal
Most Susceptible: skunks, foxes, raccoons, bats, cattle
Human Infection: dogs, cats
What is the most likely method of exposure (rabies)?
bite wound that introduces saliva in the tissues
Path the rabies virus takes thru the body
virus is inoculated into tissue –> enters either nerve endings or damaged nerve fibers located near point of entry –> migrates up peripheral nerves to brain –> demyelination and eventual neuronal death is caused –> migrates from brain to salivary glands –> infected animal is now contagious
When is an animal considered contagious?
After the virus reaches the salivary glands of the animal
What is the incubation period for rabies?
3-8 weeks, but depends on location of bite and amount of viral particles inoculated with the bite
List the 3 clinical stages of rabies.
- Prodromal Stage
- Furious Stage
- Paralytic Stage
Describe the prodromal stage of rabies
- lasts 2-3 days
- behavior changes
- dementia
- restlessness
- fly biting
- unprovoked vocalization
Describe furious stage of rabies.
excitability and seemingly uncontrolled tendency to eat or bite anything in its path
Describe the paralytic stage of rabies
- lasts 2-4 days
- generalized seizures
- ascending paralysis starting with ataxia in hind limbs
- paralysis of several facial muscles
- paralysis of respiratory muscles
Most common technique for diagnosis of rabies
post-mortem eval of brain or brainstem using immunofluorescent techniques
Recommended rabies vaccine protocols for domestic pets
- start a 12wks of age and repeat at 1yr of age
- boost every 1 or 3 years
- 3 yr vax may have specific requirements that differs by state
List 3 complications associated with the rabies vax
- allergic rxn
- skin rxn
- encephyalitis
What does an allergic rxn to the rabies vaccine look like?
- swollen muzzle/face
- shortness of breath
- severe respiratory distress
What does a skin reaction to the rabies vaccine look like?
- small, firm lump under skin that resolves in several weeks
- if mass persists (especially in a cat) investigate because it could be a vaccine induced fibrosarcoma
What does encephalitis look like in dogs?
2 forms:
- 10-12 days post vs will notice flaccid paralysis with normal cranial nerve exam; Tx with supportive care; usually resolves on its own.
- Obvious signs of CNS probs with cranial nerve deficits; prognosis poor
Describe a retorvirus
-reverse transcriptase that assists viral replication by creating DNA from viral RNA
What 2 proteins are important for diagnosing and vaccination for FeLV
p27- diagnostic testing; increases in plasma of FeLV infected cats
gp70- important in inducing immunity in host
What are the 3 subgroups of FeLV? What is associated with each subgroup?
A- least pathogenic
B- immunosuppression, neoplasia
C- severe nonregenerative anemia
All FeLV+ cats have A. Some have coinfections with B and/or C
How is FeLV transmitted?
Horizontally via mutual grooming and shared fomites (litterbox, food/water bowls)
Vertically from queen via placenta or milk
What is the nickname for FeLV?
Nice Cat Dz
How is FeLV primarily shed?
Saliva
General clinical signs of an FeLV+ cat
- pyrexia due to acute inflam. response by whole body
- neutropenia due to neutrophils going to fight (less in circulation)
- lymphadenopathy (generalized) due to virus replicating within cells of LN
List 3 Dz common in FeLV+ cats
- neoplasia (primarily lymphosarcoma)
- bone marrow suppression
- immunosuppression
Neoplasia occurs in FeLV+ cats b/c…
…of how viral and host DNA randomly rearrange resulting in cancerous cells
Bone marrow suppression occurs in FeLV+ cats b/c…
…of viral infection of cells found in the bone marrow
…of certain secondary infections
…of lymphosarcoma inflitrating bone marrow and destroying cells
Immunosuppresion occurs in FeLV+ cats b/c…
… immune cells get destroyed
What tests are used to detect FeLV?
ELISA (looks for p27) Immunofluorescence assay (confirmatory)
Cons of ELISA for FeLV testing
can get false positives and negatives
more likely to get false positive if using whole blood instead of plasma or serum
Nursing interventions for healthy FeLV+ cat
- euthanize
- keep indoor only with no other FeLV- cats
Nursing interventions for ill FeLV+ cat
- euthanasia
- treat underlying Dz with targeted therapy
- can give meds to increase RBC production if severely anemic or to stim. WBC production if leukopenic, but effects usually don’t last very long
How to prevent FeLV-
- indoor only cat
- no exposure to FeLV+ cat
What about the FeLV vaccine?
- efficacy and safety questionable
- vaccine induced fibrosarcomas
