Heat stroke occurs most commonly when:
- Animals are left in a car in warm weather
- Are outside without access to shade in hot weather
- Are exercised strenuously in the heat
- Are experiencing prolonged seizure activity.
Even on a mild day (75-80 degrees F), the temperature inside a car can raise up to 130 degrees in a few minutes. Leaving a window slightly open will NOT prevent heat stroke.
Heat stroke can also occur when an animal’s ability to cool itself becomes compromised by an airway obstruction, cardiac disease, laryngeal paralysis, or lung disease. Obesity and old age can also predispose animals to heatstroke when in hot environmental conditions. Dogs are more prone to heat stroke than humans because of their fur coat. Dogs do not have the ability to use evaporative cooling by sweating. They can only cool themselves by panting. Although it can happen with any animal, there are breeds that are predisposed to heatstroke including brachycephalic breeds (those with short noses) like bulldogs, boxers, Boston terriers, pugs, Pekingese, Lhasa Apsos, dogs with heavy, thick coats, Persian cats, hamsters, guinea pigs, rabbits, and birds.
There are a number of factors that help to precipitate heat stroke:
- Environmental temperature
- Lack of ventilation
- Muscular activity
- Coat color (dark coats absorb more heat)
- Age (older dogs have less ability to regulate body temperature and suffer the effects of increased body temperature sooner).
Complications can occur when the animal’s temperature reaches 106 degrees or higher. Problems include rapid heart rate, heart arrhythmias, severe dehydration, bloody diarrhea and vomiting from destruction of the lining of the intestinal tract, and bleeding tendencies from damage to blood clotting proteins. The prognosis for survival with heat stroke is guarded, with only about 50% of animals surviving. Without intensive efforts, many pets do not survive past 24 hours.
Treatment may include:
- Cooling baths
- Supplemental oxygen
- IV fluids
If you think your pet may be having a heat stroke, move the animal out of the sun and heat and cool him or her with water. Then transport your pet to a veterinary hospital. If available, turn on the air conditioner in the car to help cool your pet on the way to the veterinarian. If not treated immediately, pets can experience failure of multiple organ systems. As the kidneys, intestinal tracts, liver, heart, and brain become overheated, they cease functioning normally which can ultimately result in death.
If you cannot get your pet to a veterinarian immediately, soak the pet’s coat with cool water. Place your pet in a tub of cool running water or spray with a hose. Thoroughly wet the belly and inside the legs. Run the cool water over the tongue and mouth. Then place a fan nearby to cause evaporative cooling. Be careful not to cool the animal too much. While cooling, take the animal’s temperature every five minutes to prevent hypothermia (overcooling). When the temperature reaches 103 degrees Fahrenheit, stop the cooling process. As soon as possible, bring the pet to the nearest veterinarian for further evaluation and treatment. This is important because your pet may be dehydrated and need intravenous fluids or other medical treatment for organ injury. This can occur up to several days after the event.
The best treatment for heat stroke is prevention. Here are some suggestions for prevention:
- Never confine your pet in a car during warm months. Temperatures in a car can rise quite a lot higher than the outside temperature, even with the windows open. Even 10 minutes inside a hot car is enough to cause heatstroke in cats and dogs. Rabbits, hamsters, and birds overheat even faster.
- Leaving the windows in your car open “just a crack” isn’t enough to prevent heatstroke.
- Provide outdoor shade.
- Have a well-ventilated doghouse that is kept in the shade (the plastic models are quite cool inside on a hot day.
- Always have fresh, clean water available.
- Make sure you have a tip-proof bowl for water. If the dog is tied up, make sure the leash can’t cause a spill, and that the dog can always reach the water.
- Consider purchasing a kiddy pool and filling it with a few inches of clean water. This is a fun and effective way for your dog to cool down.
- Don’t allow your dog to over-exert itself. This especially applies to working dogs or overactive, playful dogs.
- If you exercise with your pet, do so during early morning or late evening hours.
- If you are traveling with your pet, be sure to stop often so that they can get out of the car and cool off.
- Keep long-haired cats or dogs clipped during summer months.
- If you have a rabbit, keep the hutch in the shade. Rabbits overheat very easily. If you have exotic pets outside (birds, rabbits, guinea pigs, etc.), make sure they have access to shade and fresh water at all times.
- See your veterinarian regularly for physical examinations and vaccinations, since an underlying disease such as obesity or heart disease can increase an animal’s risk for heatstroke.