R51163, a newly synthesized purine alkyl piperidine that produces reliable sedation in cattle, was tested in five adult bull moose (Alces alces) Compared with controls, all animals dosed with 0.4 mg/kg BW ate significantly (P < 0.05) less dry matter for at least 1 wk after treatment. Median estimates of resting metabolism, measured the day of injection. did not differ between treatment and control groups, although the coefficient of variation was almost two times larger for drugged (15%) versus control (8%) individuals. Dose response was allometric, with larger animals exhibiting longer effects.