EXPERIMENTAL REPRODUCTION OF MYCOPLASMA-GALLISEPTICUM-DISEASE IN CHUKAR-PARTRIDGES (ALECTORIS-GRAECA)

An outbreak of conjunctivitis and severe respiratory disease occurred in an integrated chukar partridge (Alectoris graeca) operation that in volved about 8000 birds. The main clinical features were conjunctiviti s and sinusitis and frequent mouth breathing, but almost no gasping or coughing. In 1000 breeders, egg production declined from 73% to 20%. Morbidity reached 100%, and losses from mortality and culling approach ed 60%. At necropsy, a conjunctivitis (often bilateral) and extensive caseated sinusitis were common. There was an occasional slight mucoid tracheitis, but no significant air sac lesions were noted. Mycoplasma gallisepticum, designated strain GM1125, was isolated and identified. Exposure of susceptible chukars to GM1125 reproduced the field disease . GM1125 was reisolated from the conjunctiva of all exposed birds 12 d ays postinfection, but infrequently from there or the respiratory syst em 36 days postexposure, even though clinical disease was still presen t. The experimental disease was confined to the conjunctiva and the up per respiratory tract. An occasional mucoid tracheitis was noted, but: generally, the lungs and air sacs were not involved. Infection was fo llowed by an appreciable serological response to M. gallisepticum.