Immobilisation of free-ranging wild animals using a new drug.

Field trials were conducted with the potent morphine-like analgesic, R33799 (Janssen Pharmaceutica; Beerse, Belgium) in South African national parks on 217 free-ranging wild animals, representing 20 different species. The drug was found to be effective and safe for a wide range of ungulates and pachyderms and Burchell's zebra (Equus burchelli) did not react to expected dosage levels. A suggested dosage regime for 19 species is given. Recommended optimal dosage rates varies from about 1 microgram per kg for pachyderms to about 10 microgram per kg for most of the larger ungulates. Xylazine and azaperone were found valuable adjuncts to R33799 in dosage ratios of 10:1 and 30:1 respectively.