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Chemical anesthesia of Northern sea otters (Enhydra lutris): Results of past field studies

January 1, 2001

Between 1987 and 1997, we chemically immobilized 597 wild sea otters (Enhydra lutris) 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.

Publication Year 2001
Title Chemical anesthesia of Northern sea otters (Enhydra lutris): Results of past field studies
DOI 10.1638/1042-7260(2001)032[0181:CAONSO]2.0.CO;2
Authors Daniel H. Monson, C. McCormick, Brenda E. Ballachey
Publication Type Article
Publication Subtype Journal Article
Series Title Journal of Zoo and Wildlife Medicine
Index ID 70022710
Record Source USGS Publications Warehouse