Epidemiology and susceptibility of pathogenic bacteria responsible for upper respiratory tract infections in pet rabbits

For 8 months, 121 pet rabbits of more than 2 months old were included in an epidemiological study aimed at determining the nature, prevalence and bacteriological susceptibility of pathogenic bacteria responsible for upper respiratory tract disease (“snuffles”). All rabbits presented with nasal discharge and sneezing at inclusion and had not received any antibiotics in the 30 days prior to the study. Nasal samples were taken from all the rabbits before they received any treatment. Isolation of bacterial strains, susceptibility testing by disk diffusion for marbofloxacin, enrofloxacin, danofloxacin, gentamicin, oxytetracycline, doxycycline, cefalexin, trimethoprim-sulfamethoxazole, and marbofloxacin MIC determination for each pathogenic bacterium were also performed. The main bacterial strains isolated were Pasteurella multocida (54.8%), Bordetella bronchiseptica (52.2%), Pseudomonas spp. (27.9%) and Staphylococcus spp. (17.4%). Snuffles was mainly due to a polybacterial infection, and the most frequently found combination was P. multocida and B. bronchiseptica (28.9% of rabbits). Marbofloxacin was shown to be the most effective agent against all bacterial strains (between 87.8% and 100% susceptibility according to strain) except B. bronchiseptica, for which gentamicin was slightly more effective (96% versus 88.9%). Compared to other fluoroquinolones tested, marbofloxacin exhibited the highest level of activity. Marbofloxacin MIC90 was equivalent to 1.320, 0.079, 1.741 and 0.490 μg/ml for B. bronchiseptica, P. multocida, Pseudomonas spp. and Staphylococcus spp. strains, respectively. In this study, marbofloxacin was shown to be a potentially good treatment option for upper respiratory tract disease in pet rabbits.