C. McCormick Brenda E. Ballachey Daniel H. Monson 2001 <p>Between 1987 and 1997, we chemically immobilized 597 wild sea otters (<i>Enhydra lutris</i>) in Alaska for the collection of biological samples or for surgical instrumentation. One drug-related sea otter fatality occurred during this time. Fentanyl in combination with diazepam produced consistent, smooth inductions with minimal need for supplemental anesthetics during procedures lasting 30-40 min. Antagonism with naltrexone or naloxone was rapid and complete, although we observed narcotic recycling in sea otters treated with naloxone. For surgical procedures, we recommend a fentanyl target dose of 0.33 mg/kg of body mass and diazepam at 0.11 mg/kg. For nonsurgical biological sample collection procedures, we recommend fentanyl at 0.22 mg/kg and diazepam at 0.07 mg/kg. We advise the use of the opioid antagonist naltrexone at a ratio of 2:1 to the total fentanyl administered during processing.</p> application/pdf 10.1638/1042-7260(2001)032[0181:CAONSO]2.0.CO;2 en American Association of Zoo Veterinarians Chemical anesthesia of Northern sea otters (Enhydra lutris): Results of past field studies article