Some greyhounds, when coming out from under anesthesia, develop a condition called malignant hyperthermia – when the body temperature rises to dangerous levels. It is caused by a metabolic disorder of the skeletal muscles and occurs more frequently in heavily-muscled dogs like the greyhound. There may be a genetic component that makes some dogs more disposed to develop this condition. Clinical signs include rapid heart rate, rapid breathing, fever, rigidity of the muscles. Treatment is administration of oxygen, IV fluids, and cooling of the dog with ice packs, cold towels, or immersion in cold water. Make sure that your vet is aware of this possible condition in greyhounds and is set up to deal with it if it occurs.