Hyperthermia in dogs

Hyperthermia occurs when the animals’ body temperature rises above a healthy range and they are unable to regulate their own body heat. This condition ranges from mild heat stress, through heat exhaustion to severe heatstroke. The terms are often used interchangeably but the conditions are actually different. All heat related illnesses require immediate attention. Heat stroke, the most severe of heat related illnesses, is a very serious condition that can lead to death even with intensive care.

Dogs are much more sensitive to heat than humans; this is because dogs primarily pant rather than sweat so have limited capacity for heat dissipation. In addition, dogs are much closer to the ground than humans, so are exposed to more heat radiating from the surface they are walking on. This surface radiation makes temperatures at dog level up to 10 degrees C hotter than at human head height. Also remember dogs’ paws can easily be burned on hot pavements.

Here in the UAE, we experience extremes of summer heat and humidity, so our dogs are even more vulnerable to hyperthermia than in other parts of the world. The humidity makes heat dissipation though panting much less effective. Some dogs are more prone to heat stroke than others. Dogs with thick fur such as Huskies, short noses (Pugs, French Bulldogs) or those suffering from medical conditions are predisposed to hyperthermia.

Heat stress is the less severe heat related illness. At this stage, dogs will show an increase in thirst and panting. As the condition worsens, it will progress to heat exhaustion then, finally, to heat stroke.

Signs and symptoms of hyperthermia in dogs

There are two commonly associated signs and symptoms of heat stress in dogs. These include:

• Increased thirst
• Increased panting

If your dog is unable to regulate their body temperature, their heat stress may progress to heat exhaustion. Signs of heat exhaustion include:

• Heavy panting
• Weakness and episodes of collapsing

If treatment is not given during heat exhaustion, it is extremely likely it will progress to heat stroke, the most severe form of heat illnesses. Signs and symptoms of heat stroke include:

• Change in gum colour (bright red or pale)
• Drooling- the drool may be thicker than normal
• Dizziness or disorientation- not able to walk straight or bumping into furniture
• Dullness and collapse
• Increased heart and respiratory rate
• Vomiting and/ or diarrhoea
• Muscle tremors- shivering of shaking
• Seizures and loss of consciousness

How to prevent hyperthermia

1. Never leave your dog inside a parked car. Even for ‘just a minute’. Even with the windows cracked open. Still, every year, hundreds of dogs left inside parked cars suffer heatstroke and die. While traveling in the car, make sure that your dog is kept in a crate that has good ventilation.
2. Make sure your dog does not stay outside too long. When they are outdoors, make sure they have plenty of water and cool, shady areas to rest in, and do not let them out during peak temperature hours.
3. Avoid walking your dog during peak temperature hours. Walk your dog in the early morning or late evening to avoid the hottest hours of the day. Take shorter walks, bring water with you and take breaks in shaded areas.
4. Keep your house cool. Many people turn off the AC when they leave the house to save money, but just like a parked car, your house’s interior temperature can rise rapidly on a hot day. If you have to leave your dog at home, keep the AC on (even at a conservative 24 degrees).
5. Make sure your dog has enough water. Remember dogs regulate their body heat by panting, resting, and drinking water, so always keep their water bowls full!
6. Board your dog during your summer vacation. While it may be tempting to leave your dog at home and have someone come check in a couple of times a day, this can be dangerous during the summer. Even leaving your dog with friends or family can be risky if your dog sitters are not informed about hyperthermia. Boarding facilities can keep them cool and safe during the hottest months.
7. Know your dog’s medical history. If your dog is older or has conditions such as heart disease, obesity, or breathing problems, it is even more imperative to keep them cool as they cannot control their body temperature so well.

How to treat hyperthermia

1. Stop all exercise and take your dog to a cooler indoor area immediately.
2. Call your veterinarian as soon as possible to advise them you are bringing your dog in and take advice about interim steps.
3. Lower their body temperature by soaking the dog with cool water. The acts in the same way as sweat does- dissipating the heat through evaporation. Do not use icy cold water! For very small dogs or puppies, use lukewarm water instead of cool.
4. Put them in front of a fan to dry off.
5. Provide cool water to drink. Again, not cold water, and no ice! Let your dog drink as much as they want, but do not try to force them to drink.

How will the veterinarian treat my dog’s hyperthermia?

With cases of hyperthermia in dogs, treatment will include intravenous fluid therapy to replace fluids and minerals. Your veterinarian will also monitor your dog for secondary complications such as shock, kidney failure, development of neurologic symptoms, abnormal clotting, changes in blood pressure and electrolytes abnormalities. This is why we recommend all cases of hyperthermia receive veterinary attention. If your dog loses consciousness or seems severely ill (vomiting or seizing) get to a veterinary hospital immediately.

Hyperthermia is a big risk during the hot, humid summer months. Dogs are more prone to hyperthermia than humans, with some breeds and individuals being especially at risk. Dogs do not build a tolerance to heat, in fact, if they have suffered hyperthermia once, they will be more susceptible to it happening again. However, with appropriate preventative measures and precautions, hyperthermia can be avoided.