Effect of acepromazine as an adjuvant to ketamine, midazolam and methadone in the chemical restraint of cats

This study aimed to evaluate the effectiveness of acepromazine as an adjuvant to ketamine, midazolam and methadone in the chemical restraint and anesthesia of cats undergoing ovariohysterectomy. We allocated 14 cats in two groups: group ketamine (GK), premedicated with ketamine 8 mg/kg, midazolam 0.3 mg/kg and methadone 0.3 mg/kg and group acepromazine (GAK), premedicated with acepromazine 0.05 mg/kg in addition to the above-mentioned drugs. At baseline (T0) and every 5 mins up to 20 mins (T5, T10, T15 and T20) after premedication, the sedation score was evaluated at 0 to 24 points. The sedation score was significantly higher at T5, T10, T15 and T20 in both groups. There were no significant differences in extubation times (3.7 ± 1.3 mins in GK; 5.2 ± 2.6 mins in GAK) and the time to reach a score equal to 0 on the sedation scale (88 ± 63.9 mins in GK; 133 ± 39.7 mins in GAK); however, the time of anesthetic release was significantly higher in the GAK than in GK (19.7 ± 6.5 mins vs 11 ± 5.9 mins) (P = 0.023). Sedation was adequate in both groups. The results indicated that the administration of acepromazine did not contribute to sedation in the protocol and could delay the anesthetic release.