Heat stroke is an emergency and
requires immediate treatment. Because dogs do not sweat (except to a
minor degree through their foot pads), they do not tolerate high environmental
temperatures as well as humans do. Dogs depend upon panting to exchange warm
air for cool air. But when air temperature is close to body temperature,
cooling by panting is not an efficient process.
Common situations that can set the stage for heat stroke in dogs
Being left in a car in hot weather
Exercising strenuously in hot, humid weather
Being a brachycephalic breed, especially a Bulldog, Pug, or Pekingese
Suffering from a heart or lung disease that interferes with efficient
Being confined without shade and fresh water in hot weather
Having a history of heat stroke
Heat stroke begins with heavy panting and difficulty breathing. The tongue
and mucous membranes appear bright red. The saliva is thick and tenacious, and
the dog often vomits. The rectal temperature rises to 104° to 110°F (40° to
43.3°C). The dog becomes progressively unsteady and passes bloody diarrhea. As shocksets in, the
lips and mucous membranes turn gray. Collapse, seizures, coma, and death
The leading cause of heart failure in dogs
is chronic valvular disease. Next
is dilated cardiomyopathy, followed by congenital heart disease and heartworms. More infrequent
causes include bacterial endocarditis and myocarditis. Coronary artery disease
is rare in dogs. It occurs only in dogs with severe hypothyroidism accompanied by
extremely high serum cholesterol levels.
Treatment: Emergency measures to cool the dog must begin at once. Move the
dog out of the source of heat, preferably into an air-conditioned building.
Take his rectal temperature every 10 minutes. Mild cases may be resolved by
moving the dog into a cool environment.
If the rectal temperature is above 104°F, begin rapid cooling by spraying
the dog with a garden hose or immersing him in a tub of cool water (not ice
water) for up to two minutes. Alternatively, place the wet dog in front of an
electric fan. Cool packs applied to the groin area may be helpful, as well as
wiping his paws off with cool water. Monitor his rectal temperature and
continue the cooling process until the rectal temperature falls below 103°F
(39°C). At this point, stop the cooling process and dry the dog. Further
cooling may induce hypothermia and shock.
Following an episode of heat stroke, take your dog to a veterinarian as soon
as possible. Heat stroke can be associated with laryngeal edema. This seriously
worsens the breathing problem and may require an emergency tracheostomy. An
injection of cortisone before the onset of
respiratory distress may prevent this problem.
Other consequences of hyperthermia include kidney failure, spontaneous
bleeding, irregular heartbeat, and seizures. These complications can occur
hours or days later.
Dehydration occurs when a dog loses body fluids faster than he can replace
them. Dehydration usually involves the loss of both water and electrolytes. In
dogs, the most common causes of dehydration are severe vomiting and diarrhea.
Dehydration can also be caused by inadequate fluid intake, often associated
with fever and severe illness. A rapid loss of fluids also occurs with heat