Feline infectious Peritinitis and coronavirus Flashcards
Cause of feline infectious peritonitis
- caused by a coronavirus (FCoV)
- NOT zoonotic
- Cat with FCoV then develops FIP. NOTE, not all cats infected with FCoV develop FIV (more common lots of cats e.g. breeders)
How is FCov shed?
SHED in FAECES
PICKED up ORALLY
4. infection with FCoV in young kittens via faecal oral transmission
What is virus classification based on?
- Genome (DNA or RNA)
- Ecology
- Enveloped or not
- Morphology
- Genome sequence similarity
- Number and sense of RNA/ DNA strands
Corona virus Genome and what it means
- RNA genome inside a lipid envelope
- Having RNA genome means these viruses can mutate and evolve quickly
- o Labile in the environment (readily/ continuously undergoing chemical physical or biological change)
Corona virus, enveloped or not?
Lipid envelope derived from hsot cell. It is essential for infectivity byt fragile. Means coronaviruses are generally short lived in environment and relatively suseptible to soap and alcohol based disinfectants
Feline coronavirus
NEVER say “your cat has coronavirus” ensure say FELINE
- LArged enveloped RNA virus -
- 2 types: Feline infectious peritonitis virus and feline enteric coronacirus
Not all cats infected with coronavirus develop into feline infectious peritonitis. What deos it depend on?
Depends on things similar to feline leukaemia virus
o virus strain ‘biotype’
o dose of virus
o immune status of cat and if can amount a good immune response
o (route of infection)
How we think feline enteric coronavirus works
if infect, some no clinical signs but they pass it on – endemic . There is a in cat mutation which leads to FIP. Cats with FIP DIE.
Do you get outbreaks of FIP
no becuase FIP isn’t faecally shed (FCoV is)
Cat ONLY gets FIP when infected with FCoV and mutation occurs to cause FIP
When do we most often see FIP
Breeders - lots of cats housed together
Pathogenesis of FIP
- Cat, oronasal infection = feline corona virus
- Replicated locally in tonsil, intestinal epithelium
- May get mild disease
- Sporadic mutation = FIP = allows virus to get in macrophages
- Once in macrophage = all over body
- then one of 3 outcomes:
a) Good cell mediated immunity, cat recovers
b) partial CMI, cat develops DRY FIP
c) poor CMI, cat develops WET FIP
What is Dry FIP?
Clinical signs
Invariably fatal
- clinical signs- fluctuating, unresponsive fever
- anorexia, depression, lethargy
- signs dependant on organ involved (abdominal? CNA? eyes?)
- Jaundice, ataxia, paresis, behavioural changes, iritis, uveitis etc
What is wet FIP and clinical signs
- Invariably fatal - rabies
- Accumulation of fluid within the body cavities e.g. abdomen
- Depression, Inappetance, lethargy, weight loss, swelling of abdomen, jaundice, hepatomegaly, dyspnoea, muffling of heart sounds. Depends where fluid accumulates
- Fluctuating, unresponsive, fever
What kind of disease is FIP?
- an immune complex disease
- immune complexes deposit in walls of small blood vessels leading to complement activation and vasculitis = inflammatory response = oedema
- Ab binds to virus, ENHANCING uptake of antigens by macrophages
- meaning Ab aren’t particularly helpful!
- Cats that don’t have antiviral antibodies don’t develop FIP = why vaccination is particularly challenging
Diagnosis of FIP
- HUGE CHALLENGE
- Definitive diagnosis – histopathology – demonstrating characteristic lesions
- Pre-mortem diagnosis (biopsy) often by a combination of clinical signs, examination of fluids, clinical pathology and FCoV serology
- If there is fluid in body cavities to be found then it should be identified and collected if at all possible OR biopsy legions – best diagnosis
