Feline Infectious Peritonitis: clinical findings, laboratory profiles and viral analysis

Feline coronavirus (FCoV) infection in cats may cause peritonitis (FIP) or a milder form of enteritis. The study is to investigate cats from private clinic and National Taiwan University Animal Hospital, with correlation of a nested reverse transcription polymerase chain reaction (RT-nPCR) assay to detect feline coronavirus highly conserved 3’ untranslated region in clinical specimens. A total of 40 cats from June 2000 to April 2004 were screened to be feline coronavirus positive and died with the diagnosis as effusive FIP . Among these 40 cats, FCoV can be detected in all of the effusion specimens. Most of the cats were purebred, with 75% (30/40)aged from 3 month to 3 year. Among them 20 with blood test data were analysed, 70% (14/20)appeared to have anemia, 90% (18/20)with lymphopenia and 70% (14/20) with A/G ratio lower than 0.7. Virus isolation were attempted using body effusion collected from positively diagnosed animals. Limited amount of coronavirus can only be detected up to the third passage by RT-nPCR. Serologic assay revealed that FCoV type I might be predominant in Taipei area. Sequence comparison were made from 475bp of 7a/7b gene, and the result shows high degree of homology to several other known FCoV strains, including FIPV strain NOR-15 isolated in the USA, which are 95.4% identical in this region.