Immobilization and physiological parameters associated with chemical restraint of wild pigs with Telazol and xylazine hydrochloride.

Abstract

We used a combination of Telazol (3.3 mg/kg) and xylazine hydrochloride (1.6 mg/kg to immobilize 144 wild pigs (Sus scrofa) with blow darts. This drug combination was safe and effective for rapidly immobilizing animals ranging in size from 34 to > 170 kg and avoided difficulties associated with hand injections. For 123 single injection immobilizations, mean (+/- SD) induction times and effective handling periods averaged 5 (+/- 2.5) and 52 (+/- 18) min, respectively, and animals generally recovered for release within 120 min of initial injections. Animals that required two injections to immobilize (n = 21) received lower initial doses of Telazol and xylazine hydrochloride than those immobilized with a single injection because of errors in estimating body sizes; we found that there was a threshold dose required to immobilize wild pigs from 2.8 to 3.3 mg/kg Telazol and 1.4 to 1.6 mg/kg xylazine. Although neither age or sex influenced immobilization parameters, animals in good condition required longer to recover than those in poor condition. However, animals immobilized with two injections recovered as rapidly as those immobilized with a single injection. Heart rates and body temperatures declined slightly during the immobilization period, but respiration rates and blood oxygen saturation levels remained stable. In general, single injection immobilizations were preferable because they minimized problems associated with injecting partially immobilized animals. because it was difficult to accurately estimate the sizes of large wild pigs (> or = 90 kg), and because wild pigs that were partially immobilized were difficult to handle, we recommend increasing the drug doses to 4 mg/kg Telazol and 2 mg/kg xylazine hydrochloride when injecting relatively large animals to assure single injection immobilizations. Although recovery periods may be prolonged, higher doses of Telazol and xylazine should be safe based on data from domestic pigs.