To investigate a possible link of malignant hyperthermia to capture myopathy, between June 1990 and July 1993 we anesthetized four black-tailed deer (Odocoileus hemionus columbianus) and challenged them with halothane and succinylcholine. Halothane had no significant effect on oxygen consumption. Succinylcholine significantly (P < 0.05) increased cardiac output (mean +/- SD), from 2.94 +/- 1.05 l/min to 5.26 +/- 1.79 l/min, and oxygen consumption, from 5.5 +/- 2.1 ml/kg/min to 10.1 +/- 2.9 ml/kg/min. Muscle biopsy specimens tested for malignant hyperthermia susceptibility responded normally to halothane and caffeine. We conclude that these deer did not experience malignant hyperthermia; suggesting no link to capture myopathy.