Multidrug-resistant wound infections are associated with greater mortality, larger costs, and longer hospitalizations than susceptible infections in canine patients.

Objective: To investigate the prevalence, risk factors, and economic impact of multidrug-resistant (MDR) infections in dogs at a tertiary referral hospital.

Methods: This was a retrospective cohort study including dogs with positive aerobic culture associated with a traumatic wound or surgical site infection between July 2018 and November 2023. Data collected from medical records included signalment, wound type, culture results, medications (antibiotics, NSAIDs, steroids, immunosuppressives), wound care, hospitalization duration, concurrent illnesses, surgical variables, and cost. Multivariable logistic regression analysis was performed to identify factors associated with MDR development.

Results: 80 dogs met the inclusion criteria, and 19 had MDR infections. Multidrug resistance increased the odds of longer hospitalization duration by 2.98 times (95% CI, 1.09 to 8.19), mortality rates by 11.8 times (95% CI, 1.24 to 112.08), and total costs by 3.57 times (95% CI, 1.3 to 9.83). Steroid use within the past year, NSAID or steroid use within 1 week before culture, and initial preculture use of either penicillin or clindamycin in the past 3 months increased the risk of MDR development by 4.51 to 7.4 times (95% CI, 1.71 to 32.09).

Conclusions: Multidrug-resistant infections were associated with greater mortality, larger costs, and longer hospitalizations. Risk factors for MDR infections included steroid use within the past year, NSAID or steroid use within 1 week before culture, and either penicillin or clindamycin within 3 months before culture.

Clinical relevance: Multidrug-resistant pathogens have clinical and economic impacts on veterinary healthcare, and there is a need to implement standardized surveillance and prevention programs in veterinary hospitals.