Different antibiotics and chemotherapeutics were tested for therapeutic efficacy in rabbits, in an experimental model using a Pasteurella multocida strain which causes hyperacute septicaemia in this animal species. Only enrofloxacin, administered in the drinking water at a concentration of 50-100 mg/l cured the rabbits, provided that a daily intake of 5 mg/kg body weight was achieved. The other drugs tested (tetracycline, spiramycin, erythromycin and a combination of sulfamerazine with trimethoprim), at doses recommended for rabbits, showed little or no activity at all, with the exception of chloramphenicol, which was only partially effective.