Clinical evaluation and prerelease management of American river otters in the second year of a reintroduction study.

In the first year (1984) of a reintroduction study, 10 American river otters (Lutra canadensis) from Louisiana were transported to Oklahoma, held for 5 days for clinical evaluation, surgical implantation with intra-abdominal radiotelemetry devices, and then released in Oklahoma. Four of 10 otters released died within 32 days. Clinical evaluation indicated that respiratory tract disease, bacterial and parasitic infections, and inanition may have contributed to the death of these otters. In the second year (1985) of the study, an exotic feline diet was fed, and the holding period for 10 otters was increased to provide time for evaluation and treatment before surgery, postsurgical acclimation to Oklahoma, and reevaluation before release. Although the initial clinical findings on otters in the second year were similar to those found in the first year, otter body weights increased, and the prevalence and severity of clinical abnormalities decreased with treatment during the second-year holding period. Three of 10 second-year otters died during the holding period, and contributing causes of death were determined to be: trauma (hepatic hematoma), inanition, renal disease, pneumonia, salmonellosis (Salmonella anatum), and a retropharyngeal abscess (Klebsiella pneumoniae). Seven healthy otters were reintroduced into Oklahoma in 1985, and postrelease deaths were not experienced.