BESNOITIOSIS IN A MINIATURE DONKEY

A 1-year-old male miniature donkey (Equus asinus) from a herd of eight was presented with a 9-month history of pruritic dermatitis, lethargy and anorexia. Physical examination revealed diffuse lichenification a nd scales involving the skin of the face, head and dorsum from the nec k to the pelvis. The main histological alteration within the superfici al and deep dermis was the presence of multiple large, spherical, thic k walled, protozoal Besnoitia cysts. In addition, the inflammatory res ponse consisted of a moderate, superficial and deep perivascular, mixe d mononuclear cell infiltrate, with epidermal hyperplasia and compact orthokeratosis. Based upon the large size of the protozoal cysts and t he ultrastructural features of the bradyzoites contained therein (cono id, polar ring, rhoptries, micronemes and microtubules), a diagnosis o f cutaneous besnoitiosis was established. Treatment with trimethoprim- sulphamethoxazole resulted in significant clinical improvement. To our knowledge, this is the first reported case of besnoitiosis in a minia ture donkey in North America.