EXPRESS: Low incidence of feline infectious peritonitis in rehomed shelter cats with known feline coronavirus status: a cohort study of 767 cats

OBJECTIVES: This study aimed to investigate long-term (up to 6 years) post-adoption outcomes in rehomed shelter cats with confirmed feline coronavirus (FCoV) infection, including the development of feline infectious peritonitis (FIP) and gastrointestinal diseases. METHODS: A cohort study was performed with a population of adopted cats from a shelter in Sydney, Australia. FCoV infection status was determined within 48 hours of shelter admission by faecal viral nucleic acid detection. Long-term health outcomes were determined via an online survey distributed by the shelter to 2641 cat owners two to six years after adoption. The relationship between FCoV infection and health outcomes was analysed using logistic regression analysis, including calculation of odds ratios for the occurrence and frequency of health outcomes based on the cat's infection status. RESULTS: A total of 882 cat owners responded to the survey (response rate = 34%). FCoV faecal test results were available for 767/882 (87%) cats with corresponding completed survey responses. The prevalence of FCoV infection in this response group was 20%. Two of 767 (0.3%) adopted cats were ultimately diagnosed with FIP after rehoming. Of the two adopted cats diagnosed with FIP, one had a negative FCoV result on shelter entry (0.2%, 1/611), and one cat had a positive result (0.6%, 1/156). Vomiting (68%, 486/719) and diarrhoea (39%, 262/680) were commonly observed in the adopted cats during the study period. CONCLUSIONS AND RELEVANCE: There was no association between FCoV infection upon initial testing and subsequent long-term development of FIP or other post-adoption health conditions. The estimated incidence of FIP 2-6 years after confirmed FCoV infection (0.6%) was lower than previously reported.