34th Annual Scientific Meeting proceedings

Objectives:

Antimicrobial resistance (AMR) in surgical site infections (SSIs) poses an increasing risk in companion animal surgery. Few studies have examined the clinical outcomes of AMR SSIs in veterinary practice. This study aimed to evaluate the differences in morbidity, mortality, and treatment costs between patients with AMR SSI, antimicrobial-sensitive (AMS) SSI, and those without SSI following surgery. Secondary objectives included identifying factors associated with the development of multidrug-resistant (MDR) SSIs.

Methods:

A retrospective review of medical records from the University of Edinburgh Small Animal Hospital was conducted for the period between June 2017 and September 2024. A total of 44 patients with AMR SSIs and 83 with AMS SSIs were matched with 126 control patients based on similar signalment, clinical and surgical parameters. Binary logistic regressions were used to assess risk factors associated with MDR SSIs.

Results:

AMR SSIs were associated with a 165% increase in total treatment costs compared to the control group, and a 97% increase compared to AMS SSIs. Patients with AMR SSIs also experienced longer post-operative hospitalisation and required more revision surgeries compared to AMS SSI and control patients. No significant difference in survival rates was observed across the three groups. Logistic regression showed an association between longer duration of anaesthesia and development of an MDR SSI when compared to the control group (OR 1.88, 95% CI [1.19, 2.96].) There was no evidence for further associations in the other groups compared.

Conclusions:

AMR SSIs represent a significant economic burden for clients and a welfare concern for affected patients.