Typhlitis Associated With Natural Trichuris sp. Infection in Cats.

Trichuris spp. infections can cause typhlitis or typhlocolitis in many species, but there are no published studies about its pathology in cats. Trichuris sp. infection in cats appears to be rare in most parts of the world but is frequent in some tropical and subtropical regions. The purpose of this study was to describe intestinal lesions associated with natural Trichuris sp. infections in cats of St. Kitts, West Indies. Comprehensive autopsies, histopathological assessment of small and large intestine, and total worm counts were performed in a cross-sectional study of 30 consecutive feline mortalities. Trichuris were found in 17 of 30 (57%; 95% confidence interval, 39%-74%) of the study cats with a median worm count of 11 (range, 1-170), indicating most cats had a low-intensity infection. Trichuris infection was associated with typhlitis but not consistency of feces or body condition score. In most cats examined, the typhlitis was categorized as mild (10/15, 67%) and, less frequently, moderate (2/15, 13%) or marked (3/15, 20%). The inflammatory infiltrate varied from predominantly eosinophilic (5/15, 33%) to neutrophilic (4/15, 27%), a mixture of eosinophilic and neutrophilic (2/15, 13%), a mixture of neutrophilic and lymphoplasmacytic (1/15, 7%), or a mixture of eosinophilic, neutrophilic, and lymphoplasmacytic (3/15, 20%). In some cats, surface erosions and catarrhal exudate were adjacent to adult worms. These findings are similar to those reported with low-intensity Trichuris infections in other species.