Vet360 Vol 03 Issue 03 June 2016 | Page 16

CPD ACCREDITED ARTICLE The FIP Jigsaw-Puzzle Dr Emma Hooijberg BVSc GPCert (SAP) DipECVCP Department of Companion Animal Clinical Studies, University of Pretoria Email: [email protected] Feline infectious peritonitis is a systemic disease caused by a mutated form of the feline enteric coronavirus (FCoV). Although the prevalence of enteric coronavirus infection is high, around 90% in catteries, only 5% of these cats, at the most, will go on to develop FIP.1 The pathogenesis of FIP is related to an aberrant immunological and inflammatory response to this virulent mutated virus (FIPV). There are two forms of FIP. The “wet” form occurs as a result of inflammation of serosal surfaces (e.g. pleura, peritoneum) and is associated with the presence of body cavity effusions. The “dry” form is characterised by granulomatous lesions in organs like the kidney, intestines, abdominal lymph nodes, liver, eyes and CNS.2 The wet form is more common, with ascites usually present.3 The wet and dry forms represent two extremes of one disease, and patients may present with clinical signs and lesions anywhere on the continuum between them. FIP is invariably fatal. There is unfortunately no simple definitive test for FIP. The diagnosis of FIP can be compared to making a jigsaw puzzle, where various puzzle pieces need to be fitted together to complete the picture. The important corner pieces Signalment: Although FIP can occur in cats in of any age, 50-70% of FIP cases occur in cats under one year of age. Cats from multi-cat households, catteries or rescue centres with high population densities are exposed to high viral loads of FCoV in faeces and easily become infected. Stressors occurring during this time, like rehoming or neutering, decrease the chance that the animal will eliminate the virus. Cats with immune-suppression are also predisposed. Purebred cats appear to be more susceptible, however the at-risk breeds vary in different studies in different regions and susceptibility may in fact be related to specific bloodlines within a breed rather than the breed itself.2 Male cats and intact individuals are predisposed.4 Effusion: Ascites, thoracic and/or pericardial effusion characterise the wet form of FIP. It should be kept in mind however that less than half of effusions in cats are caused by FIP, and it is the characteristics of the effusion, not the mere presence, that make up this important piece of the FIP puzzle.1 Results from effusion analysis, in particular total protein, albumin:globulin (A/G) ratio and PCR, have a higher diagnostic value than tests performed on blood.3 The following are typical for an FIP effusion: vet360 Issue 03 | JUNE 2016 | 16 JUNE 2016 Vet360 working.indd 16 2016/05/24 12:04 AM