Delayed onset malignant hyperthermia in two pigs.

Malignant hyperthermia developed in two Landrace x Large White pigs, 75 and 105 minutes after the induction of anaesthesia with halothane. Rapid treatment and discontinuation of halothane anaesthesia were unable to reverse the condition in the first case but were successful in the second. The delayed onset of malignant hyperthermia after delivery of halothane is unusual and for successful treatment careful monitoring and rapid and aggressive therapy are needed.