Field Anesthesia of the Maned Wolf (Chrysocyon brachyurus) in Bolivia.

Fifteen maned wolves (Chrysocyon brachyurus) were anesthetized a total of 43 times as part of a long-term ecology and health study in a remote region of northeastern Bolivia. We administered tiletamine-zolazepam (TZ) to wolves in box traps or free-ranging, from blinds or on foot, at a mean dosage of 4.6 mg/kg intramuscularly. Detailed anesthetic information was recorded in 24 of these events in 11 wolves (six males, five females), and wolves were monitored closely post procedure with very high frequency or global positioning system telemetry collars. Anesthetic induction was smooth and rapid in all cases, with a mean 6.4 min from injection to recumbency. Vital parameters were stable during the majority of procedures. As expected with this drug combination, recovery was long (mean time to standing 163 min [range: 80-235 min]) but smooth, and animals were monitored in most cases in box traps until stable for release. One case of apnea and prolonged recovery is reported. In two cases, wolves recovered normally but were found to move minimally in the 2.5-4 d postprocedure before resuming normal movements. Overall, TZ provided safe, stable immobilization of free-ranging maned wolves in remote and extreme field conditions, although postanesthesia monitoring via telemetry is recommended.