Abstract / Summary
This randomized controlled study evaluated the comparative efficacy of meloxicam and methadone on postoperative analgesia and cardiorespiratory parameters in 24 female dogs undergoing ovariohysterectomy (OHE). After premedication with acepromazine (0.05 mg/kg) and morphine (0.05 mg/kg) intramuscularly, anesthesia was induced intravenously with propofol at 6 mg/kg, titrated to effect. The dogs were maintained on isoflurane and 100% oxygen at a rate of 100 ml/kg/min. The dogs, then, underwent OHE with continuous monitoring of physiologic variables. Immediately after the final skin suture, the dogs were randomly assigned to one of three treatments: saline (SAL, n = 8), meloxicam (MEL, 0.2 mg/kg, n = 8), or methadone (MET, 0.2 mg/kg, n = 8), all administered IV. Postoperatively, cardiorespiratory parameters were recorded. Pain was assessed using three pain scoring scales. Inflammatory/stress markers (cortisol, glucose, lactate, TNFα, IL-1β) were also measured. The results showed that methadone-treated dogs exhibited lower heart rates and required less rescue analgesia compared to the SAL. The Glasgow Composite Pain Scale-Short Form was lower at 30 minutes in the MET compared to the MEL. Dogs in the MEL and MET showed some benefits in modulating inflammatory markers, which were more pronounced in the MEL. In conclusion, methadone provided more effective postoperative pain control and contributed to better cardiorespiratory stability in canine ovariohysterectomy compared to placebo and meloxicam.