Treatment of methicillin-resistant Staphylococcus aureus infection following tibial plateau leveling osteotomy in a dog

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) is 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 to treat MRSA infection following TPLO in a dog.Case Description: A 7-year-old spayed female American cocker spaniel was referred for right hind limb lameness that did not improve with conservative treatment. The 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 injury to dehisce. MRSA was detected from the purulent discharge, and chloramphenicol was then administered based on the drug sensitivity test results. Because of the continued drainage, the implants were removed after the bone union of the osteotomy site was observed. Since this did not provide any relief to the existing condition, the antibiotic was changed to vancomycin at 132 days after TPLO surgery, and the infected location was cleaned many times through a drain tube placed into the tibia. However, the infection could not be controlled. Thus, a rifampicin and vancomycin combination was started. As a result, the purulent discharge disappeared and the fistula entirely closed on the 154th day after TPLO surgery.Conclusion: A combination of rifampicin and vancomycin may be effective for treating MRSA infection at the surgical site following TPLO surgery that does not heal despite implant removal and administration of vancomycin