Influence of administration of antimicrobial medications after tibial plateau leveling osteotomy on surgical site infections: A retrospective study of 308 dogs

Objective To determine the influence of prophylactic administration of oral antimicrobial medications after tibial plateau leveling osteotomy (TPLO) on surgical site infections (SSI) and antimicrobial-resistant infections. Study design Retrospective study. Sample population Dogs treated with unilateral TPLO (n = 308) between January 2013 and December 2015. Methods Medical records were reviewed for signalment, surgically treated limb, duration of surgery and anesthesia, postoperative administration of antimicrobial medications, antibiotic agent, surgeon, and development of SSI. Statistical analyses included descriptive statistics, simple linear regression, analysis of variance, Fisher's protected least significant difference, and chi(2) testing. Results Data were collected from records of 31 dogs that did not receive antimicrobial medications and 277 dogs that did receive oral antimicrobial medications for 14 days after TPLO. Superficial incisional SSI was detected in two of 31 dogs that did not receive antimicrobial medications and in 48 of 277 dogs that did receive antimicrobial medications (P = .1194). Deep incisional SSI occurred in two of 31 dogs that did not receive antimicrobial medications and in 27 of 277 dogs that did receive antimicrobial medications (P = .5513). Antibiotic-resistant deep incisional SSI occurred in two of 31 dogs that did not receive antimicrobial medications and in 18 of 277 dogs that did receive antimicrobial medications (P = .9920). Body weight correlated with deep incisional SSI and resistant infections. Prolonged duration of surgery and anesthesia were associated with superficial incisional SSI, deep incisional SSI, and antibiotic resistance. Surgeons influenced deep incisional SSI. Conclusion Previously reported predisposing factors for infection were confirmed, but postoperative administration of antimicrobial medications was not protective against SSI nor did it predispose to antibiotic resistance in our clinical setting. Clinical significance This study does not provide evidence to support administration of prophylactic oral antimicrobial medications after unilateral TPLO.