Disorder - Malignant hyperthermia

Organ Systems Involved
Musculoskeletal

Alternative Names
Anaesthetic hyperthermia; Malignant hyperpyrexia; Malignant hyperthermia syndrome; Feline stress syndrome

Presenting Signs

Signs of this condition only become evident when an affected animal is placed under general anaesthesia, is extremely stressed, has been treated with some types of muscle relaxant drugs or has been exposed to certain toxins. Prior to such an event the animal appears to be normal, although some cats with the condition may appear abnormally well muscled.

Signs of the condition include muscle twitching and spasms, extremely high body temperature, increased heart rate, increased breathing rate and fluctuations in blood pressure. These changes result in severe metabolic disturbances which can lead to heart failure, kidney failure, widespread blood clot formation and death.

Cats at Risk

Cats that have an immediate relative known to have the condition

Treatment

Medical: immediately stop administration of anaesthetic agents or muscle relaxants if they are implicated as a cause of the malignant hyperthermia. Aggressive cooling, supplemental oxygen administration, intravenous fluid therapy and administration of dantrolene sodium (muscle relaxant) are the mainstays of treatment.

PubMed References
Malignant hyperthermia

Contributor
Zoë J K Hamilton