Heatstroke is a life-threatening emergency in dogs that is almost entirely preventable, causing organ failure and death in animals exposed to excessive heat, particularly in cars and during vigorous exercise in hot weather.
Heatstroke causes acute suffering through hyperthermia, neurological signs including seizures, and multi-organ failure. Death from heatstroke is painful and prolonged. The majority of cases involve leaving dogs in cars or exercising in heat — both entirely preventable through owner education. Brachycephalic breeds have a dangerously impaired ability to cool themselves and require particular care in warm weather. Emergency cooling must be initiated immediately as brain damage and organ failure begin within minutes of core temperature elevation above the critical threshold.