RESUMO
The efficacy, safety, physiologic effects, and reversibility of butorphanol-medetomidine-midazolam (BMM) immobilization were evaluated in black-footed cats (Felis nigripes) and compared between captive and wild animals. Nine captive and 14 wild black-footed cats were hand injected into an accessible hind limb muscle group with the BMM combination. The captive cats (captive group) received a lower dose of the combination (butorphanol, 0.25 ± 0.03 mg/kg; medetomidine, 0.06 ± 0.01 mg/kg; midazolam, 0.13 ± 0.02 mg/kg), whereas the wild cats received a higher dose (butorphanol, 0.53 ± 0.11 mg/kg, medetomidine, 0.13 ± 0.03 mg/kg, midazolam, 0.27 ± 0.05 mg/kg). Two capture methods were required to restrain the wild cats; previously collared cats were tracked and excavated out of their burrows during daylight hours (excavated group), whereas uncollared cats were randomly located using spotlights and pursued by a vehicle at night (pursued group). Inductions were rapid and no spontaneous arousals occurred. Mean arterial blood pressure in all cats was within normal limits for domestic cats. Initial rectal temperatures varied greatly among the groups, but decreased in all groups as the immobilization progressed. In the pursued animals, heart rates and respiratory rates were initially elevated. All cats had moderate hypoxemia, hypocapnia, and metabolic acidosis. Intramuscular administration of naltrexone, atipamezole, and flumazenil resulted in rapid, uncomplicated recoveries. BMM is thus a safe, effective immobilizing drug combination for both captive and wild black-footed cats, but higher doses are required in wild animals. The capture methods exerted a greater influence on the physiology of the immobilized animals than did the doses of the drugs used. Although this drug combination can be used safely to immobilize black-footed cats, supplemental oxygen should always be available for use, especially in pursued animals due to hypoxia.
