Abstract
Background: In recent years, surgical site infections caused by drug-resistant pathogens have emerged as a cause of concern in small animal practice. In this report, methicillin-resistant Staphylococcus aureus (MRSA) infections associated with tibial plateau leveling osteotomy (TPLO) have been reported. However, there have been no reports on the treatment of MRSA infection following TPLO in dogs. This case report describes the use of a combination of vancomycin and rifampicin for the treatment of MRSA infection following TPLO in a dog.
Case Description: A 7-year-old spayed female American cocker spaniel was referred for right hindlimb lameness that did not improve with conservative treatment. This dog was diagnosed with cranial cruciate ligament rupture, for which TPLO was performed. Once the surgical wound was closed, the dog licked the skin on the surgical site, causing the wound to dehisce. MRSA was detected from purulent discharge, and chloramphenicol was then administered based on the results of the drug sensitivity test. Because of the continued drainage, the implants were removed after bone union of the osteotomy site was observed. Since this did not lead to any improvement, the antibiotic was changed to vancomycin at 132 days after TPLO surgery and the infection site was repeatedly washed through a drain tube placed into the tibia. However, the infection was not controlled. Thus, a combination of rifampicin and vancomycin was initiated. As a result, the purulent discharge disappeared and the fistula closed completely at 154 days after TPLO surgery.
Conclusion: A combination of rifampicin and vancomycin may be effective for the treatment of MRSA infection of the surgical site following TPLO surgery that does not heal despite implant removal and administration of vancomycin.

Key words: Dog, Infection, MRSA, rifampicin, TPLO