Trichuris spp. infecting domestic cats on St. Kitts: identification based on size or vulvar structure?

BACKGROUND: On St. Kitts, a high number of cats are found to be infected with Trichuris. Necropsies have shown pathologic changes related to the infections. In order to determine if these changes were related to a particular Trichuris species, a review of the original identifications of Trichuris campanula and Trichuris serrata was conducted. FINDINGS: Based on the review of published descriptions of T. campanula and T. serrata, it is hypothesized that the presence or absence of a vulvar projection and a bacillary band can be used to differentiate the two species and these criteria are more accurate than nematode or egg size. The Trichuris in cats on St. Kitts were similar in size to the description of T. campanula, but had both a vulvar projection and bacillary band. CONCLUSIONS: Based on the morphological characteristics, all of the Trichuris found in twelve domestic cats were determined to be T. serrata. Cats without pathologic changes are required to further investigate if the changes are species or strain related.