Anesthetic and Postanesthetic Effects of Alfaxalone-Butorphanol Compared with Dexmedetomidine-Ketamine in Chinchillas (Chinchilla lanigera)

Effective and safe anesthetic protocols are required for a variety of surgical and diagnostic procedures in chinchillas. Alfaxalone, a new anesthetic agent in the United States, can be administered intramuscularly and subcutaneously and is therefore potentially useful as an anesthetic induction agent in chinchillas. This study compared the anesthetic efficacy and postanesthetic effects on food intake and fecal output of a combination of intramuscular alfaxalone (5 mg/kg) and butorphanol (0.5 mg/kg; AB anesthesia) with a combination of dexmedetomidine (0.015 mg/kg) and ketamine (4 mg/kg; DK anesthesia) in a blinded, randomized, complete crossover design in chinchillas (n = 12). The AB combination resulted in a rapid induction of short-term anesthesia, which was inconsistent in depth and length. In contrast, the DK protocol resulted in rapid induction of a consistent level surgical anesthesia and rapid recovery after administration of atipamezole (0.15 mg/kg IM). Food intake and fecal output were significantly more decreased in the AB group (food, -65.9% +/- 17.7%; feces, -72.2% +/- 18.7%) than in the DK group (food: -37.7% +/- 8.2%, feces: -16.5% +/- 15.8%) during the first 24 h after anesthesia. Food intake and fecal output remained significantly reduced compared with preanesthetic levels for 4 to 5 d after anesthesia with both protocols. Compared with the AB protocol, the DK protocol provided superior anesthetic efficacy and had fewer postanesthetic side effects in chinchillas and is therefore a more suitable injectable anesthetic combination for this species.