Mrl. Cattet et al., REVERSIBLE IMMOBILIZATION OF FREE-RANGING POLAR BEARS WITH MEDETOMIDINE-ZOLAZEPAM-TILETAMINE AND ATIPAMEZOLE, Journal of wildlife diseases, 33(3), 1997, pp. 611-617
The objective of this study was to determine if the potent alpha(2) ag
onist, medetomidine, and its specific antagonist, atipamezole, could b
e effectively used to immobilize polar bears (Ursus maritimus). Specif
ically, our goal was to develop a drug combination containing medetomi
dine that addressed some of the problems such as prolonged recovery ti
me, non-reversibility, and poor analgesia that have been identified wi
th the currently preferred drug combination, zolazepam-tiletamine (Tel
azol(R) or Zoletil(R)). During 1995 and 1996, 51 free-ranging polar be
ars along the western coast of Hudson Bay, Canada, were immobilized wi
th a combination of medetomidine, zolazepam, and tiletamine (MZT). Imm
obilization with MZT was characterized by a short induction time, low
volume, reliable and predictable immobilization and reversibility, ade
quate analgesia, and relative safety in handling for field personnel.
Few adverse physiological effects were observed in any target animals
with the exception of a single bear which convulsed and died shortly a
fter it was reversed from anesthesia with atipamezole. We conclude tha
t MZT is an effective drug combination for immobilizing polar bears. H
owever, because of an unexplained mortality, further investigation of
the physiological effects of MZT and atipamezole is warranted.