Macrodendritic ulcerative keratitis and conjunctival lymphoid hyperplasia in horses with equine herpesvirus-2 and equine herpesvirus-5 infections.

Objective: The aim of this study was to describe the clinical, confocal microscopic, histologic, and virologic features of horses with macrodendritic ulcerative keratitis and conjunctival lymphoid hyperplasia associated with equine herpesvirus-2 and equine herpesvirus-5 infection.

Animal Studied: Four foals with bilateral ocular disease.

Procedures: Complete ophthalmic examination was performed for each horse, and corneal samples were collected for cytology and microbiologic evaluation, including virus isolation and molecular diagnostics for the equine herpesviruses.

Sarcocystis neurona: parasitemia in a severe combined immunodeficient (SCID) horse fed sporocysts.

Sarcocystis neurona was isolated from the blood of a 5-month-old Arabian foal with severe combined immunodeficiency. The foal had been inoculated approximately 3 weeks previously with 5 x 10(5) sporocysts that were isolated from the intestines of an opossum and identified by restriction enzyme analysis of PCR products as S. neurona.