Zoletil® immobilization of Wild boar (Sus scrofa L.)

Abstract

Many Wild boar (Sus scrofa L.) experiments carried out over the last 15 years required capturing and handling of the animals. Since Zoletil® N.D. has been used successfully to immobilize many wildlife species, we tested it on 46 free-ranging wild boars, captured in box traps and on 17 hand-reared wild boars. They were anesthe- tized in the box trap with the help of a hypodermic pistol. The freeze dried form of Zoletil® N.D. allowed us to administer strong dosages despite the very small volumes required by our method of teleanesthesia. Mean induction time (loss of equilibrium, collapse and effective lying down) was 3’ 41’’ and did not depend on the administered dosage (r = 0.14). With a dosage rate between 6.8 and 9.2 mg/kg of body weight, all animals slept between 15 minutes and one hour. Sleep was deeper and longer when more than 9.2 mg/kg were administered. The maximum dosage tested without lethal effect was 15 mg/kg. Therefore we recommend a mean dosage of 8 mg/kg, which allows for a 15% estimation error of body weight. The very agitated recovery phase is a critical period during which the animal must be kept under constant surveillance to prevent any heart or respiratory failure due to added stress. The use of an immobilizing agent for Wild boar allows people to manipulate it safely, without much risk for the animal.