Heat stroke in dogs - what signs should you look out for?

Estimated Reading Time 4 minutes
Heat stroke in dogs - what signs should you look out for?

Did you know that dogs barely sweat? Their main way of cooling down is panting, where heat is lost in the air they breathe out. During hot or humid weather this process isn’t very effective, and they also have fur coats they cannot take off. All these factors mean that dogs can be prone to heat stroke and if a dog’s temperature rises above 42°C it can lead to death either at the time or a few hours later from organ failure.

Are you concerned about your pet? Meet a vet online!
  • Included free as part of many pet insurance policies
  • Help, treatment and if you need it, a referral to your local vet
  • Open 24/7, 365 days a year

Symptoms of heat stroke in dogs

Early signs of heat stress may be subtle and it is important to know what is normal for your dog. In severe cases, the dog goes into shock and becomes unconscious. In increasing order of severity, the signs to look out for include:

  • Becoming anxious, barking, whining or trembling

  • Faster and heavier panting than normal

  • Seeking shade or reluctance to move

  • Excessive drooling or increased thirst

  • Increased heart rate

  • Elevated rectal temperature over 40°C (104°F)

  • Deep red or purple gums that feel dry when touched

  • Vomiting and diarrhoea

  • Mental dullness or glassy eyes

  • Weak and wobbly

  • Difficulty breathing and collapse, which may progress to seizures

  • Loss of consciousness

Causes of heat stroke in dogs

Being trapped in a warm car, or other hot and enclosed space, is the most common cause of heat stroke in dogs. You can prevent heat stroke by never leaving your dog in a car in the summer. It can take as little as 15 minutes for a dog to die of heat-related illness. During the summer in the UK the temperature inside a car can reach 56°C (133°F). Dogs can also suffer from heat stroke if they are in the sun for too long without shade, or if they are exercised in warm weather without water and rest periods. It is also very important to take into account humidity as a high humidity will lead to heat stroke quicker as it decreases heat loss from panting.

Some dogs are more susceptible to heat stroke than others:

  • Obese dogs

  • Short noses (brachycephalic breeds)

  • Young and small dogs

  • Thick or long haired breeds such as nordic breeds (Huskies), Samoyed, Pekinese

  • Health conditions such as heart or lung disease

Treating heat stroke at home

If a dog shows symptoms of heat stroke it is important to act quickly.

  • Move the dog to a cool, quiet area

  • Actively cool the dog using cold water, such as a bucket and sponge or shower

  • Do not submerge the dog’s head in water as this can cause aspiration pneumonia

  • Cold wet towels can be placed on the stomach, armpits and pads. Refresh them frequently otherwise, they can trap the heat and exacerbate the problem

  • Take the dog’s rectal temperature every five minutes, if it is safe to do so, until the temperature is below 39.5°C (103°F). Normal body temperature is around 37.8°C (100°F)

  • If despite the above measures the condition of your dog does not improve within a few minutes seek veterinary help

  • Under the Animal Welfare Act 2006 it is considered a criminal offence for an owner to leave their dog in a hot car. If you find a dog trapped in a car try to contact the owner first, and then call 999 to alert the police. In an emergency situation, safely break the window, remove the dog and follow the steps above

  • After a mild episode of heat stroke you should seek advice from a veterinarian to ensure that your dog has no additional complications

  • Important: never give anti-inflammatory medication to a dog with heat stroke as this can cause serious harm

Veterinary treatment of heat stroke

Whole body cooling is the focus of treatment for heat stroke. Intravenous fluid therapy may also be needed to treat symptoms of shock and electrolyte imbalances. Blood tests are used to evaluate internal organ function. Dogs that have had heat stroke may need to stay in intensive care for several days until they have stabilised and normal organ function has resumed.

When to see your physical vet

  • If you need to visit a vet you should continue to cool your dog whilst on the way to the clinic. For example, use several cold wet towels and offer plenty of fresh cold water to drink

  • Call the vet to alert them that you are on the way

  • In severe cases of heat stroke, rapid veterinary treatment is required - every minute counts!

  • Here is a link to a useful temperature guide for exercising dogs that is worth considering when deciding whether to exercise your dog

Still worried?

Book a video appointment to have a chat with one of our vets.

Published: 17/07/2019
Last updated: 12/05/2021

Contact a UK vet online right now!

What can we do for your furry friend?

  • Assess how they are in that exact moment
  • Answer your questions, offer advice, and make a plan about your concerns
  • Recommend easily available, over-the-counter pet health products when sufficient
  • Make a referral to a local vet when necessary
Book an appointment
  • Included free as part of many pet insurance policies Included free as part of many pet insurance policies
  • Help, treatment and if you need it, a referral to your local vet Help, treatment and if you need it, a referral to your local vet
  • Open 24/7, 365 days a year Open 24/7, 365 days a year
Low cost consultations, 24 hours a day.Low cost consultations, 24 hours a day.

With FirstVet, the vet clinic and pet shop are only one tap away. Get fast advice, trusted care and the right pet supplies – every day, all year round.


25 Horsell Road


N5 1XL