Symptoms of dog stroke

Dog stroke symptoms occur when heat production or input exceeds heat output so body temperature rises to dangerous levels. In hot, humid weather it is difficult for dogs to lose heat, because evaporative cooling cannot occur effectively. Strenuous exercise under these conditions can lead to a dangerous increase in body temperature. Similarly, when dogs are closed in cars in the sun, their panting saturates the air with water vapor, so further heat loss is impossible. Symptoms of dog stroke include prostration of the dog with its tongue hanging out, and unresponsiveness to the owners' attentions, dry mucous membranes, dehydration and high body temperature.

As the body temperature rises, the metabolic rate increases, and more heat is produced. In addition, panting or sweating, or both, leads to dehydration and circulatory collapse, so it is more difficult to transfer heat to the skin. Once the body temperature exceeds 41.5 - 42.5 Celsius, cellular function is seriously impaired and consciousness is lost.

Brachycephalic dogs, such as Boston Terriers have an added disadvantage in temperature regulation and present more dog stroke symptoms than other breeds. The short nose and convolutions in the wall of the pharynx increase the work of breathing, especially when the dogs pant. This increased work is an additional source of body heat, and the anatomy of the upper airway probably makes evaporative cooling less effective.

Therapy for dog stroke is to reduce body temperature and to restore circulatory function as rapidly as possible. For this reason, the dog is placed in a cool water bath to reduce body temperature, and also receives intravenous fluids to rehydrate it by expanding its circulatory volume and restoring the ability of the circulation to redistribute heat within the body.