[Halothane anesthesia of several hours' duration in swine of the German Landrace breed, selected for resistance to malignant hyperthermia].

The malignant hyperthermia syndrome is widely spread in pigs of the German Landrace. This has precluded the use of halothane anesthesia. The advent of homozygous halothane-negative strains stimulated us to test whether such animals were suitable for longduration halothane anesthesia. Nine sows of the German Landrace (n = 4, homozygous halothane-positive (H+); n = 5, homozygous halothane-negative (-)) were used. Anesthesia was induced by Azaperon/Metomidat-HCL followed by intubation and exposure to halothane. All 4 halothane-positive animals died within 45-90 min following the onset of halothane administration, while all 5 halothane-negative animals survived a 4-5 h deep anesthesia without problems. Thus, homozygous hylothane-positive strains of German Landrace pigs may be surgically anesthetized for long durations with halothane anesthesia.