Nine pharmaceutical preparations were administered to healthy chicks which had been introduced into a poultry farm very highly contaminated with M. gallisepticum and H. gallinarum. They were chlortetracycline plus vitamin, erythromycin, mikamycin, nitrofurantoin, spiramycin, streptomycin plus penicillin G. sodium salt, thiophenicol glycinate, and vitamins A, D3, and E.
Three untreated control flocks were established. All of them were proved to have been infected with both organisms from clinical and postmortem findings, serological tests, and isolation of these organisms at the end of the experiment.
Clinical and postmortem examinations revealed that chlortetracycline plus vitamin, spiramycin, and thiophenicol glycinate had prophylactic effects upon the experimental chicks, as compared with the control ones.
