Bacterial and fungal culture and sensitivity from rabbits presenting with nasal discharge

Abstract

Bacterial respiratory infection is one of the most common diseases encountered in rabbits in general practice (Oglesbee, 2011). Various bacteria such as Pasteurella multocida, Pseudomonas aeruginosa, Moraxella catarrhalis, Bordetella bronchiseptica and mixed anaerobes have been implicated as causative agents. Historically, Pasteurella has been implicated to be a common isolate linked to rhinitis, sinusitis, otitis, conjunctivitis, dacryocystitis, bacteremia and subcutaneous abscesses. Many infections are subclinical and the true incidence of Pasteurellosis within the rabbit population is unknown (Oglesbee, 2011). Responsible use of antibiotics in veterinary practice is of the utmost importance and bacteriological culture and sensitivity testing is recommended prior to prescription of antimicrobial medications. The objective of this retrospective study was to investigate which bacteria and fungi were frequently found within respiratory secretions from the nasal cavity of 171 rabbits presenting with nasal discharge. Deep nasal swabs placed into charcoal media were analysed at an external commercial pathology laboratory, Pinmoore Animal Laboratory Service (PALS). Aerobic, anaerobic and enrichment cultures were performed to detect the bacteria and fungi present and to assess the sensitivities to the isolates. Preliminary data show that many bacteria were found within the obtained samples, with the main isolates being Pasteurella spp (14.6%), E.coli (8.77%), Pseudomonas spp (8.19%) and Moraxella spp (7.6%). There was a low prevalence of yeasts (0.58%) and Aspergillus fumigatus (0.58%). If antibiotic treatment is deemed necessary before culture and sensitivity data are obtained, this study emphasises that enrofloxacin (Baytril, Bayer) provides a broad spectrum of cover with percentage sensitivities of 92% for Pasteurella spp, 80% for E.coli, 57.1% for Pseudomonas spp and 84.6% for Moraxella spp. Trimethoprim and sulfamethoxazole (Sulfatrim, Virbac) provides a medium spectrum of cover with percentage sensitivities of 64% for Pasteurella spp, 80% for E.coli, 21.4% for Pseudomonas spp and 46.2% for Moraxella spp. Oxytetracycline provides a medium spectrum of cover with percentage sensitivities of 88% for Pasteurella spp, 53.3% for E.coli, 28.6% for Pseudomonas spp and 69.2% for Moraxella spp. Penicillin provides a narrow spectrum of cover with percentage sensitivities of 56% for Pasteurella spp, 0% for E.coli, 0% for Pseudomonas spp and 53.8% for Moraxella spp.