Besnoitia bennetti in Two Mexican Burros

Abstract

Besnoitia bennetti infection was detected in two Mexican burros from a closed herd of 15 animals in Maryland. Cystic stages, which were about 1.0 mm in diameter, were found in the testicle of a male and in the skin of the perineum and teat of a female. The superficial location of the cysts on the teat suggests the potential for traumatic rupture and oral transmission during nursing by a foal. The wall of the cysts was 10–15 μm thick and consisted of four layers, the outer of which was birefringent. Within each cyst was a mass of organisms each about 1–2 by 5 μm. Various histochemical stains were used. This is the first confirmed diagnosis and report of natural infection with B. bennetti originating within the United States. © 1973, American College of Veterinary Pathologists. All rights reserved.