Lidocaine-ketamine-propofol total intravenous anesthesia in two chinchillas (Chinchilla lanigera)

This case report describes the use of a lidocaine-ketamine-propofol total intravenous anesthesia (TIVA) protocol in two chinchillas (Chinchilla lanigera). Two 4-year-old, 0.60 and 0.63 kg, intact female chinchillas underwent general anesthesia for dentistry. The first chinchilla presented for occlusal adjustment, but mucopurulent vaginal discharge was identified following sedation. Diagnostic findings were most consistent with an open pyometra, and an exploratory laparotomy with ovariohysterectomy was performed. Histopathology confirmed uterine adenocarcinoma. The second chinchilla underwent intraoral extraction of the right mandibular fourth cheek tooth because of advanced periodontal disease. Both chinchillas were premedicated with buprenorphine, dexmedetomidine, midazolam, and ketamine, followed by intravenous induction of anesthesia with an initial popofol bolus (0.5 mg kg^-1), lidocaine (2 mg kg^-1), ketamine (1.6 mg kg^-1), and additional propofol titrated to effect (1.5 and 0 mg kg^-1 for chinchillas 1 and 2, respectively). Chinchilla 1 was administered one additional intravenous propofol bolus (0.5 mg kg^-1) during ovarian pedicle manipulation. Anesthesia was maintained with TIVA, using constant rate infusions of lidocaine (100 μg kg^-1 minute^-1), ketamine (0.6 mg kg^-1 hour^-1), and propofol [1.6 mg kg^-1 hour^-1 (chinchilla 1) and 2.0 mg kg^-1 hour^-1 (chinchilla 2)]. Orotracheal intubation was achieved in both chinchillas using a 2.0 mm uncuffed endotracheal tube. Both chinchillas maintained spontaneous ventilation, although decreased respiratory rates, mild hypercapnia, and intraoperative hypothermia occurred. Recovery was uneventful in both cases. These cases suggest that this anesthetic protocol may provide satisfactory anesthesia for both short- and intermediate-duration procedures in chinchillas; however, further investigation is warranted to evaluate its safety and efficacy in a larger population. A review of the literature indicates this is the first report describing lidocaine-ketamine-propofol TIVA in chinchillas and the first report of uterine adenocarcinoma in this species.