Feline Viruses Flashcards
What does FIP stand for?
Feline Infectious Peritonitis
What causes FIP?
Caused by a mutated corona virus
Regular feline corona virus (FeCV) is restricted to what part of the body? How does FIP differ?
Restricted epithelial cells lining the gut.
The mutation enables the virus to infect macrophages and spread systemically
What is the approximate prevalence of FeCV? What does this imply about the virus?
~40%, it can remain in the body for months to years with no clinical signs, typically is a non issue
(similar GI signs as other corona viruses)
In what age cats is FIP typically seen?
Young
What is the immune response to FIP?
Insufficient, because there is no display of viral antigens on the monocyte surface
Explain the vieremia of FIP. What are the implications of this?
veiremia is very short (peaks around day 7), This means RT-PCR to diagnose is difficult
Clinical signs of FCoV
usually a systomatic, sometime enteritis (rarely fatal)
When does FeCoV start shedding?
3-4 days post infection
What are the two FCoV shedding patterns?
Transiently and persistently
What are the possible outcome of FCoV?
Transient infection (70%)
Persistant infection (13%)
Resistant (5-10%)
FIP (1-3%) RARE
How long does the a cats immunity for FCoV last?
short lived, this means cats can be re infected by the same or different strain within 2-3 weeks
How long do transiently shedding FCoV cats shed for?
2-3 months
What type of virus is FIP?
Corona virus, ss + RNA, enveloped
How does FIP spread?
Not transmissible from cat to cat!! All cats with FIP have their own mutation that happened to them. (but transmissible in the lab)
What part of virus mutates in FIP? What implications does this have?
Mutation in specific parts of spike proteins, therefore mutated virus is able to attach to different types of cells
Specifically mutation @ furine cleavage site of spike protein or at C protein
Clinical signs of wet FIP?
- abdominal distension due to ascites
- high specific gravity of the abdominal fluid (containing granulocytes)
- fever
- high specific gravity of the abdominal fluid
- ophthalmological signs (Ocular lesions and uveitis)
- granulomas of omentum and other organs
What clinical sign happens in wet and dry FIP?
ophthalmological signs (Ocular lesions and uveitis)
Fever
What determines if cat gets wet or dry FIP?
We dont know
What FIP is more difficult to diagnose?
Dry
Clinical signs of dry FIP
- hardly any fluid/ascites
- opthalmological signs
- lack of appetite
- fever
- jaundice
- diarrhea
- weight loss
- neuro signs (difficulty walking, standing, functional paralysis over time)
What is one of the most difficult to diagnose viruses in felines?
FIP, especially dry FIP. Use clinical hx, can only get a likely diagnosis until specialized immunohistochemistry laboratory biopsy test is done (but cat has to be dead)
How can you test for FIP? What are the pros and cons?
Antech mRNA PCR (mRNA indicates active replication) (has a high false positive rate and viremia peaks at day 7 so hard to catch but can do while cat is alive)
IDEXX PCR - good test but requires tissue sample
Biopsy with immunohistochem- good but need biopsy
Is there a vaccine for FIP?
No
Is there a treatment for FIP?
Not legally, GS-441524 available on black market, very similar to human drug Remdesivir. Unlikely to be approved for cats until approved for humans
What are the clinical implications of GS-441524?
It either works to it doesn’t, there no in-between, typically not helpful for neurological FIP
What does FIV stand for?
Feline Immunodeficiency Virus
What does FLV stand for?
Feline Leukaemia Virus
What type of virus is FLV?
Lenti (ie retro virus) ssRNA enveloped virus
What type of virus is FIV?
Lenti (ie retro virus) ssRNA enveloped virus
What clades of FIV are most common in Canada?
B and C
(A-E through out the world)
What is the primary receptor and co-receptors for FIV?
Primary receptor: CD134 (activated by CD4+ T lymphocytes)
Co Receptor: CXCR4 and CCR5 (same as human HIV)
What cells can FIV replicate in?
Differenciated cells (B-cells, astrocytes, macrophages, T cells, etc)
What are the stages of FIV?
Acute mild febrile phase —> asymptomatic phase–> slow progression with many little problems —> FAIDS
In what stage are antibodies, CD4 Tcells and FIV highest?
FIV particles highest in acute phase and symptomatic phase/ FAIDS (low in asymptomatic)
Antibodies highest in asymptomatic phase (drop off when T cells drop)
T cells gradual decline from infection, lowest in symptomatic phase /FAIDS
What are the clinical signs of FIV?
-Chronic gingivostomatitis
-Chronic rhinitis
-Lymphadenopathy
-Immune-mediated glomerulonephritis (proteinuria (primarily albuminuria, hypoproteinemia, ascites,, dyspnea (due to pleural effusion or pulmonary edema), and/or peripheral edema)
-Weight loss (in late stage)
-Many concurrent viral, bacterial, fungal and protozoal infections
- Stomatitis
When does clinical FIV usually occur in cats?
Older cats
FIV is a disease of __________
Management. Can live a long normal life span if managed correctly.
Can FIV be passed on to their kittens?
It can be but not always
If your cat has FIV what one way to prevent it from spreading?
Prevent cat from fighting with other cats
the SNAP ELISA tests for what?
FIV and FeLV
Specifically in SNAP ELISA tests for FIV and FeLV what is being looked for and why?
FIV checks for antibodies (can do this because cat is always infected), FeLV checks for antigens (because regressor cats (completely cleared infection) will have antibodies for FeLV so need to check antigens
What cat viruses has vx (in this section) ?
ONLY FeLV
Give some reasons why FIV vx was discontinued?
limited protection, increased risk of injection site sarcoma w booster, FIV tests became positive, only used on a case by case basis and many cats that were at risk were not the ones getting vaccinated
What kind of virus is FeLV?
retrovirus, ssRNA, enveloped
But not that closely related to FIV
What are clinical signs of feLV
Dyspenea, pale, anemia, lymphadenopathy, lymphoma (variety of disease including leukaemia)
How is FeLV transmitted?
Contact with saliva (during grooming and sharing food dishes), nasal secretions, blood, faces, milk
What is the most important factor in determining the clinical outcome of FeLV?
The cats age at time of infection (difficult for adult cats to get infected, even in lab settings, this is VERY different compared to FIV)
What are the possible outcomes of FeLV?
1) Cat gets infected and completed eliminates the virus (regressor)
2) Cat have transiet viremia that either becomes regressor or verimia
3) viremia cat goes into latent infection or lifelong infection (will develop leukosis and or tumours) Persistent !
4) Stress or immunosuppression can force out of latent infection persistent!
After a positive FeLV test why is it important to retest?
If get a positive test not sure if it will be a regressor or presistant cat, retest in 3 month to see if cleared the infection
What are the 4 subgroups of FeLV? Which are most important?
A B C T (A and B most important)
All FeLV infected cats get infected with what subgroup?
FeLV-A
How do cats get FeLB?
FeLV-A and endogenous FeLV recombine to form FeLV-B
What are some implications of FeLV-B infections?
FeLV-B infections arise de novo within individual cats (cannot be transmitted cat to cat), more than one distinct FeLV-B variant can circulate in a cat, FeLV-A and FeLV-B can circulate together
What is the Clinical implication of being infected with both A and B?
Appearance of FeLV-B increases the frequency of neoplastic diseases, leads to higher viral load
Is there a vx for FeLV?
YES, but none are 100%
What kind of FeLV vx should be used? Why?
Non adjuvated, modified live or recombinant Vx
Decrease risk of inj site sarcoma
What are some considerations with the FeLV Vx?
- none provide 100% protection
- Cats can still get infected BUT most will not get progressive form
- Only recommended for cats that go outdoors!!
