Feline Coronavirus Prevalence in 493 Cats With Chronic Diarrhea

Abstract

Background: Chronic diarrhea (CD) is common in cats, with unknown etiology in many cases. Objectives: To establish the prevalence of feline coronavirus (FCoV) and other enteropathogens in cats with CD. Animals: Veterinarians at a feline specialty practice examined 493 cats with CD. The breed of three (0.6%) was unknown; 373 (75.7%) were non-purebred, and 117 (23.7%) purebred. Methods: Retrospective database review of 586 fecal sample results of an RT-PCR and PCR diarrheal panel. Results: Feline coronavirus was found in 321 (65.1%) of 493 cats with CD. FCoV RNA and Clostridium perfringens toxin DNA were detected in 377 (64.3%) and 319 (54.4%) samples respectively: 206 (35.2%) samples were positive for both pathogens. Feline coronavirus was the sole pathogen detected in 118 (23.9%) cats. Samples from 203 cats under 1 year old were significantly (p = 0.0001) more frequently FCoV positive than samples from older cats (166/224 [74.1%] samples vs. 211/362 [58.3%]). FCoV RT-PCR positivity peaked in February (p = 0.016) and March (p = 0.0064). Other detected pathogens included Giardia spp. (8.4%; 49/586 samples); Tritrichomonas blagburni (8.4%; 46/586); Cryptosporidium (5.1%; 30/586); Campylobacter jejuni (3.4%; 17/497); Campylobacter coli (1.6%; 8/497); Salmonella spp. (0.8%; 5/586); panleukopenia virus (0.8%; 5/586); and Toxoplasma gondii (0.5%; 3/586). Sixty-nine cats gave 162 samples: 54/69 (78.3%) cats were FCoV positive, 39/54 (72.2%) persistently so. Conclusions: If FCoV is non-pathogenic, as often assumed, its having the highest rate of positivity in CD cases is difficult to explain. If pathogenic and overlooked, key diagnostic and therapeutic opportunities might be missed.