Field immobilization of muskrats (Ondatra zibethicus) for minor surgical procedures

A combination of ketamine hydrochloride and xylazine hydrochloride at doses of 50 mg/kg and 5 mg/kg, respectively, was used to immobilize 48 muskrats (Ondatra zibethicus) from October 1993 to November 1994 in Tennessee (USA). Mean (+/-SD) time for induction was 2.97 +/- 1.1 min. After a mean (+/-SD) duration of 27.2 +/- 3.5 min intramuscular yohimbine hydrochloride at a dose of 0.125 mg/kg was administered. Mean (+/-SD) recovery time was 48.1 +/- 21.6 min. All anesthetic inductions were smooth and sufficient depth of anesthesia was achieved to allow surgical collection of adipose tissue. Recovery times were more variable than expected. There was a significant (P < or = 0.05) drop in heart rate, respiratory rate, and body temperature during anesthesia. One animal died during recovery.