Reversible immobilization of Eurasian otters with a combination of ketamine and medetomidine

The efficacy and safety of the combination of medetomidine and ketamine was examined in order to establish an adequate chemical immobilization protoco l in the Eurasian otter (Lutra lutra) for use during translocation projects in Spain. Thirty-eight Eurasian otters ranging in body mass from 3 to 8.7 kg (mean 5.3 kg) were successfully anesthetized on 82 occasions. The dosage of ketamine was 5.1 +/- 0.8 (3.4-6.6) mg/kg (mean SID; range) combined wit h medetomidine at a dosage of 51 +/- 8 mug/kg (34-66 mug/kg). In most cases anaesthetic effect occurred within 3 min and the mean induction time was 5 .5 +/- 3.2 min. The mean pulse rate was 95 beats/min. The mean respiratory rate was 32 respirations/min while the relative oxyhemoglobin saturation wa s 93%. According to these results, this anesthetic protocol is considered s afe and can be recommended in wild caught Eurasian otters for immobilizatio n during translocation projects. It is safe, rapid and can be reversed when needed with atipamezole. However caution is required as heart depression r esulting in bradychardia may occur.