Pasteurella associated rhinitis of rabbits: efficacy of penicillin therapy.

Thirty adult New Zealand white rabbits with chronic rhinitis were obtained from a commercial breeding colony. Penicillin sensitive strains of Pasteurella multocida were isolated from the upper respiratory tract of 28 (93%) of these rabbits. The diseased rabbits were treated with either intramuscular penicillin or penicillin nasal spray for 10 days and monitored for clinical signs of rhinitis and for the presence of Pasteurella multocida in the nasal passages. Rabbits receiving penicillin therapy by either route showed significant remission of the clinical signs of rhinitis during the study period; however, following treatment there was not significant difference in the prevalence of rhinitis between the treated groups and the untreated group. This was due in part to the considerable but non-significant improvement shown by the untreated group. This improvement which was not due to penicillin therapy may have been due to stabilization of environmental factors. The prevalence of Pasteurella multocida in the upper respiratory tracts of either the treated or untreated rabbits did not change significantly during the study period.