Due to certain anatomic, physiologic, and behavioral features, rabbits have a higher risk for anesthesia-related mortality and GI complications as compared with other domestic species. The major concerns are related to potential underlying disease, challenges with intubation and intravenous catheter placement, stress, pain, and perianesthetic thermoregulation. Choice of anesthetic protocol may also affect procedural outcome, as some immobilization agents may be associated with more adverse effects than others. For example, gas immobilization alone should be avoided in rabbits due to stress-related apnea, commonly observed during induction, and laryngospasm and bradycardia that may develop with some medetomidine-based drug combinations.
This retrospective study investigated the incidence of and potential risk factors for perianesthetic mortality and nonfatal GI complications (eg, reduced fecal output, diarrhea, dysphagia) in a population of pet rabbits admitted to an exotic animal referral hospital. Of 185 rabbits that underwent 210 anesthetic events, 6 died during sedation or general anesthesia and 4 died within 72 hours postoperation (mortality rate, 4.8%). Of the 10 rabbits that died, 7 had received combinations of medetomidine and ketamine and 8 had undergone elective procedures; none had undergone multiple anesthetic events. Cardiorespiratory complications were the suggested cause of death in 7 rabbits. GI complications developed in 38% of the surviving rabbits 72 hours after the anesthetic event despite preemptive metoclopramide or ranitidine administration. Higher body weight significantly increased the risk for post-anesthetic GI complications.
