Abstract
Effective pain control after orthopedic surgery is essential in veterinary practice, particularly in small-breed dogs with low physiological reserves. This study aimed to compare the analgesic efficacy and tolerability of five postoperative pain protocols across nine surgical procedures. A retrospective analysis was conducted in 205 small-breed dogs (≤7 kg) undergoing orthopedic surgeries. Dogs were assigned to one of five analgesic protocols: (A) carprofen, (B) tramadol-lidocaine-ketamine continuous-rate infusion, (C) butorphanol continuous-rate infusion, (D) hydromorphone continuous-rate infusion, and (E) multimodal analgesia combining local anesthetics, hydromorphone, and meloxicam. Pain was assessed at 6, 12, 24, 48, and 72 h using the Glasgow Composite Measure Pain Scale-Short Form. Analgesic efficacy was evaluated using pain trajectories, area-under-the-curve analysis, and pain resolution rates, and adverse effects were recorded. Dogs receiving multimodal analgesia achieved the most rapid and sustained pain relief, with all patients reaching pain resolution by 48 h. Hydromorphone alone showed comparable efficacy but was associated with more adverse effects, while tramadol-lidocaine-ketamine showed delayed pain relief and the highest rate of severe side effects. Multimodal analgesia provides superior pain control with acceptable safety in small-breed dogs undergoing orthopedic surgery, supporting its use based on surgical invasiveness and individual patient response.