Heatstroke and Hyperthermia
Heatstroke is an elevation in body temperature to 106ºF or above (normal is 100.5º-102.5ºF) which is not caused by inflamation or infection. A combination of high ambient temperature, high humidity and poor ventilation can lead to animals no longer being able to keep their bodies at a normal level. Animals do not sweat like we do, rather they cool themselves by panting and radiation of body heat from the skin surface. Damage to many different organ systems and cells can occur very quickly leading to dehydration, heart arrhythmias, dissiminated intravascular coagulation (a bleeding disorder), kidney failute, liver damage, and many other problems.CausesAs previously stated, high ambient temperature, high humidity, and poor ventilation can be factors leading to heat stroke. Older animals, very young animals, dehydrated animals, obese animals, and long or thick-coated animals have more difficulty regulating their body temperature. Brachycephalic breeds with shirt, flattened noses such as Pugs, Bulldogs, Pekingese, and Boxers are especially susceptible to heat stroke, because their restricted breathing does not allow enough air exchange for rapid heat loss. Upper airway disease, such as laryngeal paralysis, can also lead to restricted breathing and high body temperature. Prolonged seizure activity may cause hyperthermia very quickly because of constant muscle contractions.SymptomsSome of the symptoms normally seen include panting, excessive salivation, collapse and seizures. Bloody vomit or diarrhea may also be present.TreatmentTreatment should begin as soon as possible to minimize the effects of the heat on the animal’s body. The patient should be cooled to 103ºF over approximately 30 minutes. Treatment usually includes IV fluids, rinsing with cool water, and correcting any underlying problems that are causing the high temperature (ex control seizures, assist ventilation, etc). Many patients require hospitalization for several days to monitor and treat and disorders caused by the fever.