Fatal cysticercosis by Taenia crassiceps (Cyclophyllidea : Taeniidae) in apresumed immunocompromised canine host

Cysticercosis in a canine host (Canis familiaris) attributable to the taeni id cestode Taenia crassiceps is reported for the first time in North Americ a. Numerous parent and daughter cysticerci occurred in a massive intrapleur al and intraperitoneal infection in an apparently immunocompromised host. T he largest cysticerci were ovoid to elongate, 5-9 mm in maximum length, and armed with 32-34 rostellar hooks in 2 rows; small hooks measured 114-143 m u m long ((x) over bar = 124 +/- 8.2 mu m), and large hooks were 156-180 mu m ((x) over bar = 163 +/- 7.4 mu m). Taenia crassiceps is widespread in bo real North America and, like a number of other taeniids, constitutes a pote ntial risk as a zoonotic parasite. The immunological status of the host may be important in determining the outcome of infections for this and other t aeniids in atypical hosts.