The effect of opioid and acepromazine premedication on the anesthetic induction dose of propofol in cats

The median effective dosage (ED50) for induction of anesthesia with propofo l was determined by using the up-and-down method in 31 unpremedicated cats, in 30 cats premedicated with butorphanol, 0.4 mg/kg body weight (BW), and acepromazine, 0.1 mg/kg BW, intramuscularly, and in 30 cats premedicated wi th morphine, 0.2 mg/kg BW, and acepromazine, 0.1 mg/kg BW, intramuscularly. The dose required for a satisfactory anesthetic induction in 50% of unprem edicated cats (ED50) was 7.22 mg/kg BW and of premedicated cats was 5.00 mg /kg BW. The reduction in dose was statistically significant in both premedi cated groups compared with no premedication. There was no significant diffe rence in ED50 between premedication regimes. Cyanosis was the most common a dverse effect observed in all groups following anesthetic induction with pr opofol.