A 5.1 kg, 7-year-old, castrated Maltese dog with a tibial plateau-leveling osteotomy (TPLO) in the right hindlimb 42 days prior to presentation. The patient’s right hind limb showed lameness, intermittent limping, and atrophy, and had never experienced rehabilitation since TPLO surgery. The patient showed a pain reaction at the end of the stifle extension, and an increased body temperature was identified on the medial side of the right hindlimb compared with the left hindlimb using a digital thermal imaging device. In addition, a type of lameness, partial weight bearing in the right hindlimb, was also identified in the gait analysis. The pain was relieved by applying a cold pack and transcutaneous electrical nerve stimulation and the patient was trained on muscles that were atrophied during treadmill exercise. In this study, physical therapy and rehabilitation exercises controlled pain and induced rapid recovery, indicating that rehabilitative intervention is required after TPLO surgery.