Epidemiological observations on stomach worms of donkeys in Morocco.

Over two consecutive years, weekly examinations for the presence of nematodes were conducted on 185 stomachs from donkeys originating mainly from the Rabat, Casablanca and Settat regions of Morocco. All the animals, except one, were infected by at least one of four helminth species. Trichostrongylus axei was found in 93.5%, Habronema muscae in 89.7%, H. majus in 85.4% and Draschia megastoma in 1.1% of donkeys. Most animals were infected by two (23.8%) or three (71.9%) species. High burdens of T. axei were observed in the winter of both years and in the mid-summer of the second year. Peak burdens of Habronema were found at various times throughout both years. There were more adult H. majus than H. muscae. The periods of peak levels of infection by these parasites were related to environmental conditions suitable for the development and survival of infective larvae of T. axei and for the build-up of muscid fly vectors of Habronema and Draschia spp.