Common bacterial pathogens and antimicrobial resistance trends cultured from respiratory, ear, dental and nasolacrimal duct infections in rabbits (2018-2024): 74 isolates.

Abstract

As rabbits become increasingly popular pets, there is an increase in this species receiving veterinary care, including antimicrobial therapy. To reduce the risk of antimicrobial resistance, it is important to perform culture and susceptibility (C&S) testing. However, empirical antibiotics based on known likely pathogens are often prescribed while C&S is pending or without performing C&S. This study aims to identify the common bacterial organisms isolated from infections involving the head of rabbits and investigate antimicrobial resistance patterns of these bacteria. Medical records for all rabbits with C&S testing from ear abscesses, dental abscesses, upper respiratory infections, or nasolacrimal duct infections were examined from two private veterinary hospitals in Sydney, NSW, Australia, between 2018 and 2024. Ninety samples were evaluated, of these samples, 10 were negative, one cultured normal respiratory flora and eight cultured only mixed anaerobes. After excluding these samples and repeat submissions (n = 5), 66 anaerobic and aerobic cultures, isolating 74 bacterium, were available for evaluation. The most commonly isolated bacteria were Staphylococcus spp. 16.2% (12/74), Streptococcus spp. 14.9% (11/74), Pseudomonas aeruginosa 13.5% (10/74), Enterobacter spp. 6.8% (5/74) and Escherichia coli 6.8% (5/74). Antimicrobial resistance of these isolates was assessed for penicillin, trimethoprim-sulfamethoxazole (TMS), enrofloxacin, marbofloxacin and chloramphenicol. High resistance to penicillin was noted among the commonly isolated bacteria, excluding Streptococcus spp. Gram-positive cocci and Escherichia coli demonstrated favourable susceptibility towards TMS and chloramphenicol. Understanding common bacterial pathogens and likely susceptibility patterns is crucial for selecting appropriate antimicrobial therapy.