What is heat stroke in dogs?

Heat stroke is a life-threatening condition that’s brought on by a sudden rise in body temperature. It commonly affects pets who are exercised outside on a hot day or are carelessly left in a car or conservatory during warm weather. Our emergency vets see hundreds of cases of heat stroke in dogs every year and, tragically, many of these prove to be fatal.

Read our advice articles below, all written by vets, and watch our video for help and support on heat stroke and some of the conditions relating to it.

Signs & symptoms

Spotting the signs of heat stroke early, and seeking emergency treatment, can massively increase your dog’s chance of survival.

In the early stages of heat stroke, your dog is likely to appear restless and distressed. They may also pant heavily and drool. As their condition worsens they will begin to lose coordination and eventually collapse.  It’s worth noting that normal rectal temperature for dogs is around 38.6°C (101.5°F) to 38.9°C (102°F) and anything above this is abnormal. Other signs of heat stroke include:

  • Rapid breathing
  • Racing heart
  • Overheating (skin hot to touch)
  • Glassy eyes
  • Unsteady on feet
  • Gums turning a bluish-purple or bright red colour
  • Vomiting
  • Seizures
  • Unconsciousness
  • Collapse

If you spot any of these signs please contact your vet straight away or, out of hours, your nearest Vets Now pet emergency clinic or 24/7 hospital.

At-a-glance infographics

Do you know the signs of heat stroke?

Read our infographic to understand more about signs and symptoms

Find out more

How quickly does a car heat up in hot weather?

Click on this at-a-glance guide to find out how hot it can get in your car

Read more

Your dog walking temperature guide

Read our summer dog walking temperature guide infographic

Read our guide

Diagnosis & treatment

If you suspect your dog has heat stroke call your vet or, out of hours, your nearest Vets Now as they will be in the best position to offer advice on your next steps.

On arrival at the vet, your dog will receive a physical examination and undergo a series of tests to determine the treatment required. If their condition is severe they will require urgent, intensive care. Your dog may be placed on a drip and given supplemental oxygen depending on whether they’re suffering breathing difficulties. Once their temperature begins to fall and their breathing is under control further diagnostic tests will be carried out.


The simplest way to ensure your dog doesn’t succumb to heat stroke is preventing it from happening in the first place. Our article on how to keep dogs cool explains some methods for this in more detail but, in general, you should:


Heat stroke can lead to organ failure very quickly. As a result, the survival rate for dogs diagnosed with the condition is poor. One of the largest studies ever carried out into the prognosis and outcome of dogs with heat stroke showed a mortality rate of 50%. Another study into heat-induced illness in dogs found that those cooled before arriving at the vet had a much lower mortality rate (19%) than those not cooled (49%).