Suspected malignant hyperthermia syndrome in a miniature pot-bellied pig anesthetized with isoflurane

Hyperthermia developed in a 7-week-old Vietnamese pot-bellied pig after isoflurane anesthesia for routine ovariohysterectomy. Shivering and a sudden increase in heart rate were noticed 90 minutes after anesthetic induction, both of which persisted throughout the remaining anesthetic period. Rectal temperature increased from 37 C immediately after anesthetic recovery to a peak of 41.5 C, and remained high for 18 hours. Treatment included external cooling and treatment with dantrolene sodium. Malignant hyperthermia was suspected to be the cause of the clinical signs in this pig, but specific tests to support this diagnosis were not performed. This report illustrates that hyperthermia may develop in this breed of swine during isoflurane anesthesia, and rectal temperature should be monitored during and after the anesthetic period.