Enteropathogen co-infection in UK cats with diarrhoea

Individual enteropathogen infections in healthy and clinically ill cats are well described, but prevalence and patterns of enteropathogen co-infection have only been reported on a limited basis. We studied enteropathogen co-infection in diarrhoeic UK cats using results of a real time PCR assay for 8 enteropathogenic species; feline coronavirus (Co), feline panleukopenia virus (Pa), Clostridium perfringens (Cl), Salmonella enterica (Sa), Giardia spp. (Gi), Tritrichomonas foetus (Tr), Cryptosporidium spp. (Cr), and Toxoplasma gondii (To). Age, gender, breed and history were recorded. PCR panels from 1088 diarrhoeic cats were available for analysis.

Overall enteropathogen prevalence was 56.9% (Co), 22.1% (Pa), 56.6% (Cl), 0.8% (Sa), 20.6% (Gi), 18.8% (Tr), 24.4% (Cr) and 1.0% (To). Prevalence of Co, Gi and Tr was higher in pedigree cats compared to non-pedigree cats (DSH) and prevalence decreased with increasing age for Co, Pa, Gi, Cr and Tr. Co-infection was common: ≥2 enteropathogens were detected in 62.5% of cats, and 13.3% of cats had ≥4 enteropathogens. Mean ( x¯) enteropathogen co-infection 2.01 (±1.3 SD), was significantly higher in pedigree cats ( x¯ =2.51) compared to DSH ( x¯ =1.68) and decreased with age ( x¯ =2.64 <6 months, x¯ =1.68 for >1 yr). More cats were negative for all 8 enteropathogens tested (12.7%) than expected. When exact combinations of co-infection were examined, Tr tended to be found in combinations with Co, Cl, and Gi.

Multiple infections should be considered the most likely result of faecal testing in cats, and case management needs to take this into account. In contrast, the relatively high percentage of cats negative for all 8 enteropathogens tested could indicate an innate resistance to infection. Alternatively it could indicate a lack of exposure to these 8 enteropathogens or the presence of other enteropathogens not assessed by this assay.