Feline infectious peritonitis

FACT SHEET What is feline infectious peritonitis (FIP)? o Central nervous system lesions due to encephalitis and/or myelitis, usually multifocal
and slowly progressive (e.g. ataxia, hyperaesthesia, nystagmus, seizures, behavioural
! FIP is a fatal disease in cats caused by feline coronavirus (FCoV). New drugs show promise changes, paralysis, cranial nerve defects).
for effective treatment but are not yet licensed.
! FCoV infection is ubiquitous in multi-cat environments, however only a small proportion of
FCoV-infected cats develop FIP. Diagnosis
! FIP is caused by FCoV variants which arise in the individual cat by mutation(s) and ! Definitive diagnosis is by histopathology with positive immunostaining for FCoV antigen
replicate to high concentrations in monocytes/macrophages. The FCoV variant type, viral within the lesions.
load and the cat’s immune response all likely play a role in determining whether FIP
! Blood changes due to FIP can include: lymphopenia, non-regenerative anaemia,
develops following FCoV infection.
increased total serum protein, hyperglobulinaemia, a low albumin/globulin ratio (A:G),
! Risk factors for FIP include: hyperbilirubinaemia, microcytosis, high α-1 acid glycoprotein (AGP) levels.
o Young age (>50% of cases are cats <2 years old)
o Stress (e.g. adoption, neutering, boarding) ! Effusions are non-septic exudates with high protein levels (with a low A:G) and a low cell
count (typically <5 x109/l cells, mainly neutrophils and macrophages).
o Cats living close together in multi-cat households.
! Positive FCoV RNA RT-PCR results on fluids (e.g., effusions, CSF, but not blood) or fine
needle aspirates (FNAs, of e.g. kidney, liver, mesenteric lymph nodes), especially when
Transmission & infection high viral loads are detected by quantitative RT-PCR, are suggestive of FIP but do not
! FCoV is primarily transmitted via the faecal-oral route. Cats shed FCoV in their faeces a few confirm the diagnosis.
days after infection and continue for weeks or months; others become infected via contact ! Presence of FCoV antigen-positive cells in fluids or FNAs with changes consistent with
with faeces in litter trays followed by ingestion (e.g. grooming). FIP is very suggestive of FIP.
! FCoV remains infectious for a few days to weeks but is readily inactivated by heat and most ! Serum FCoV antibodies are not diagnostic of FIP as they only signify previous FCoV
detergents and disinfectants. infection or vaccination.

Clinical signs & lesions

! FCoV infection is usually subclinical, but some cats, and especially young kittens, develop Treatment
diarrhoea (usually self-limiting). ! Without new, potentially curative, anti-coronaviral drugs (e.g. GC376, GS-441524 - not
! In cats that go on to develop FIP fluctuating fever, weight loss (or failure to gain weight), yet licensed), FIP has a very poor prognosis. Veterinarians in many countries are not
anorexia and lethargy are common. allowed to obtain or prescribe these unlicensed drugs but many clients are sourcing the
! FIP can also include clinical signs due to: drugs themselves online. In some countries vets are supplying diagnostic and treatment
o Effusions (ascites, thoracic and/or pericardial effusion) (e.g. abdominal monitoring support, without providing or prescribing the drugs, to help support cat
enlargement/swelling or dyspnoea) welfare. An accurate diagnosis is important to prevent unnecessary use of these drugs.
o Granulomatous lesions in abdominal and/or thoracic organs (e.g. renomegaly, chronic ! Successful treatment indicators include improvement of clinical signs (e.g. reduced
diarrhoea, lymph node enlargement) effusion, weight increase) and laboratory parameters (e.g. decreasing globulin, bilirubin
o Ocular inflammation (e.g. uveitis and/or chorioretinitis which can manifest as and AGP levels).
granulomatous "mutton-fat" keratic precipitates, anterior chamber fibrin and dense ! Supportive treatment can include appetite stimulants for anorexia, effusion drainage
aqueous flare, retinal perivascular cuffing) (e.g. thoracocentesis if dyspnoeic), anti-pyretic drugs.

If you found this ABCD information valuable, please tell a colleague. To download the ABCD fact sheets, or the full disease guidelines, please visit our website: www.abcdcatsvets.org
The ABCD is an independent organisation supported by Boehringer Ingelheim (the founding sponsor of the ABCD) and Virbac. January 2021
 Feline
Feline Infektiöse
infectious Peritonitis
peritonitis

FACT SHEET Control

! FCoV infection risk can be reduced by keeping cats in small (£3),
well-adapted groups (to reduce stress) with strict hygiene (sufficient,
frequently cleaned litter trays with clumping cat litter or outdoor

© Hannah Dewerchin, Ghent University, Belgium

© The Feline Centre, Universität Bristol

access for toileting).
! In multi-cat households, where separation of cats is feasible, faeces
(free of cat litter) or rectal swabs can be tested by quantitative RT-
PCR for FCoV RNA to identify shedders and separate them from non-
shedders. In case of a negative result the possibility of intermittent

© Marian Horzinek, ABCD

shedding has to be considered. To check this, multiple sampling
(ideally at least 3 x each 1-4 weeks apart) is necessary.

Prevention
! FCoV-infected cats should be kept in a low-stress environment.
! An intranasal FIP vaccine is available in some countries for cats over
16 weeks. However its efficacy is doubtful and it is ineffective in cats
previously infected by FCoV. ! Fluid accumulation in a Sphinx cat with FIP. ! Granulomatous lesions of the liver in a cat with FIP.

© The Feline Advisory Bureau, UK

© Eric Déan, Véthoeil, France

© Albert Lloret, ABCD

© Albert Lloret, ABCD

! Radiograph of a cat with FIP showing thoracic and ! Uveitis in a cat with FIP ! Hyphaema in a cat with FIP.
abdominal effusion.