Date of Award:


Document Type:


Degree Name:

Master of Science (MS)


Natural Resources

Committee Chair(s)

Frederick F. Knowlton


Frederick F. Knowlton


Robert Schmidt


Mike Wolfe


Stan Allen


Gray wolves (Canis lupus) are frequently captured with leg-hold traps for reintroduction, relocation to reduce depredations on livestock, or as subjects for research projects. Wolves captured with leg-hold traps often sustain injuries to their feet, legs, and teeth during struggles to escape. Other studies have shown that the use of tranquilizer devices on leg-hold traps reduces such injuries to coyotes. This study (1) assessed whether use of tranquilizer trap devices (TTDs) on leg-hold traps reduced the severity of injuries sustained by captured wolves, and (2) examined the effects TTDs have on nontarget species caught during wolf capture operations. Data were collected from 112 wolves (21 pups and 91 adults), as well as 114 nontarget animals from 9 species captured during 1996 in Minnesota. Laboratory evaluations, including radiographs and necropsies of foot and leg injuries of 37 adult wolves captured in Livestock Protection Company (LPC) drag traps equipped with TTDs containing propiopromazine hydrochloride, indicated a significant reduction in severity of injuries compared to traps without TTDs (n = 23) or equipped with placebo TTDs (n = 15). None of the 42 nontarget individuals captured in traps equipped with TTDs containing propiopromazine hydrochloride succumbed to drug overdoses. Injuries were significantly less severe among nontarget animals caught in traps equipped with TTDs containing the tranquilizer, and fewer non target animals (7%) captured in traps equipped with TTDs loaded with propiopromazine sustained severe injuries and had to be destroyed, compared to nontarget animals captured in traps not equipped with propiopromazine TTDs (42%).