Objective: To compare safety of propofol with a medetomidine-midazolam-ketamine (MMK) combination as an anesthetic agent in mallard ducks.
Animals: 12 healthy adult female mallard ducks.
Procedure: Each duck was anesthetized twice in a crossover study design with 5 days between randomized treatments. Ducks were given medetomidine (50 micrograms), midazolam (2 mg), and ketamine (10 mg) in combination, i.v., or propofol (10 mg, i.v., followed by 1- to 4-mg boluses). Systolic, diastolic, and mean arterial pressures, heart and respiratory rates, and esophageal temperature were recorded before anesthesia and every 5 minutes after induction for 30 minutes, and at 5 minutes after reversal with atipamezole (250 micrograms) and flumazenil (25 micrograms; MMK group) or last bolus (propofol group). Arterial blood samples from 8 ducks were collected before anesthesia, 5, 10, 15, 30 minutes after induction, and after reversal or last bolus.
Results: 8 ducks survived the MMK anesthesia; 1 duck died and 3 ducks required resuscitation to prevent death. All ducks survived propofol anesthesia. Ducks anesthetized with either anesthetic agent had a significant increase in arterial carbon dioxide tension and decrease in arterial oxygen tension, arterial pH, and esophageal temperature. Ducks given MMK had a decrease in mean arterial pressure and respiratory rate, whereas ducks given propofol had an increase in respiratory rate. Rapid reversal of the effects of MMK was achieved with atipamezole and flumazenil. All physiologic variables, except esophageal temperature in the propofol group, returned to approximate baseline values after reversal or last bolus.
Conclusions: The MMK combination in unsafe for use in ducks. Ducks can be anesthetized safely with propofol but should be monitored and ventilated artificially.