Equine pythiosis in Costa Rica: report of 39 cases.

Thirty-nine pythiosis equine cases, were studied at the Veterinary Medicine School of the National University of Costa Rica, between 1981 and 1984. Lesions were located in different parts of their anatomy: anterior and posterior extremities, abdomen, thorax, breast and mammary gland, and were characterized by their tumoral appearance with necrotic tissue in which yellow-white coral-like necrotic masses, called kunker or leeches were shown. Splendore-Hoeppli like phenomenon and eosinophilic inflammatory reaction around the hyphae, was microscopically observed. Pythium sp. (Hyphomyces destruens) was isolated in Sabouraud dextrose agar from ground kunkers. Immunodiffusion (ID) to diagnose this disease in equines, was performed with success. Immunotherapy was applied to 5 of affected horses, and three were cured. Some epizootiological aspects of the pythiosis are also discussed.