Field evaluation of Telazol? and ketamine- xylazine for immobilizing black bears

Abstract

Telazol? and ketamine-xylazine have become the 2 most frequently used chemical immo- bilants for black bear (Ursus americanus). We compared effects of Telazol and ketamine- xylazine (KX) in 60 black bear immobilizations in relation to 5 response parameters during summers of 1992-1994 in southeastern Arkansas. Induction times did not differ (P = 0.99) between immobilants, and no induction-dosage relationship was observed with either Tela- zol (P = 0.52) or KX (P = 0.70). Heart rates did not differ (P = 0.28) between immobilants, and both induced mild tachycardia. With use of Telazol, respiration rate increased (r = 0.53, P = 0.06) with increasing body temperature. No correlation (r = -0.54, P = 0.34) be- tween respiration rate and body temperature was detected with use of KX. Compared to Telazol, use of KX resulted in higher (P = 0.06) incidence of hyperthermia (i.e., body tem- perature >400C), with more than twice as many KX-treated bears becoming hyperthermic as Telazol-treated bears. Increased pulmonary ventilation may have been a factor in minimiz- ing heat stress in Telazol-immobilized bears. With use of KX, there were 4 episodes of sud- den spontaneous recovery by immobilized bears. Recovery of Telazol-immobilized bears was gradual and predictable, although restraint time was 2.5 times longer than with KX due to lack of an effective antagonist to Telazol. Based on our observations, we recommend use of Telazol over ketamine-xylazine as a safe and effective immobilant for black bears.