Infection Rate following TPLO Procedure with and without a Course of Postoperative Antibiotics: A Retrospective Study of 308 Dogs

Introduction: Minimizing implant-associated infections and antimicrobial resistance would improve patient outcome and client satisfaction. We aimed to compare infection and antimicrobial-resistance rates in dogs treated with oral antimicrobials following TPLO versus dogs not given oral antibiotics. We hypothesized postoperative antimicrobials would not protect against infection and would result in higher incidence of multidrug-resistance.

Materials and Methods: Medical records from unilateral TPLO procedures and TPLO implant removals between January 2013 and December 2015 were retrospectively analysed.

Results: Body weight correlated inversely to age but had a linear relationship with surgical and anaesthesia times. The study had a 16.2% SSI, 9.4% positive culture, and 6.5% antibiotic-resistant infection rates. Higher weight correlated with positive culture and resistant infections. Longer surgical and anesthesia times predisposed to SSI, positive culture, and antibiotic resistance. The surgeon directly influenced infection rate. Postoperative antibiotic usage was not protective against infection and did not predispose to antibiotic resistance.

Discussion/Conclusion: Results prove no advantage to routinely use prophylactic oral antibiotics in postoperative TPLO patients. Contrary to common belief, no increased antibiotic-resistance occurred in patients treated with postoperative antibiotics. The study supports well-known risk factors for infection including weight, surgical time, and anaesthesia time. Results raise concern for increased infection risk related to specific individuals, with potential factors including intraoperative contamination, poor tissue handling, differences in surgical implants, and nasopharyngeal carriers of multidrug-resistant organisms.

Acknowledgement: There was no proprietary interest or funding.