Effects of 3 morphine doses, in combination with acepromazine, on sedation and some physiological parameters in dogs

This study evaluated the effects of 3 morphine doses combined with acepromazine, on sedation and physiological parameters in 5 clinically healthy dogs. Four treatments were administered intramuscularly in a randomized, blinded, crossover design: acepromazine, 0.05 mg/kg, alone (ACP) and acepromazine plus morphine at doses of 0.25, 0.5, and 1.0 mg/kg body weight (BW) (AM_0.25, AM_0.5, and AM_1.0, respectively). Sedation scores and cardiorespiratory variables were evaluated for 120 min after drug administration. The sedation scores were significantly higher with the AM_0.25 and AM_1.0 treatments than with the ACP treatment. At 30 min the scores were 36% to 66% higher with AM_1.0 than with AM_0.25 and AM_0.5, respectively, but these differences were not significant. The physiological variables remained acceptable for dogs. The results of this study do not support the use of AM_0.5 over AM_0.25 to improve sedation in dogs, but they do indicate that sedation may be greater with AM_1.0 than with AM_0.25 and AM_0.5. Studies with a greater number of samples are warranted to confirm this statement.