Heatstroke in dogs

Written by Dr Andrew Miller MRCVSDr Andrew Miller MRCVS is an expert veterinary working in the field for over 10 years after graduating from Bristol University. Andy fact checks and writes for Pure Pet Food while also working as a full time veterinarian. Pure Pet FoodPure Pet Food are the experts in healthy dog food and healthy dogs featured in media outlets such as BBC, Good Housekeeping and The Telegraph. Working with high profile veterinary professionals and nutritionists, Pure Pet Food are changing dog food for the better. - Our editorial process

Most dogs love to be outside, whatever the weather. Many dog owners will relate to being dragged outside by their pet to play in the garden despite the freezing weather conditions. But when the summer rolls around, being outside with your dog in the sunshine is a pleasure, whether that be in the garden, at the seaside or in a beer garden.

However, dogs can suffer from many sun-related conditions, such as sunburn, dehydration and heatstroke. As a dog owner, it is crucial to be aware of the severe impact any prolonged time in the sun can have on your furry friend.


Heatstroke in a dog is much like it is in humans. It is caused when a dog’s body temperature rises and they are unable to bring it back down to a normal temperature of 38-39°C. Developing quickly and severely, heatstroke is deadly and even a minor increase of just 4°C can have fatal consequences.

Heatstroke exists in two forms, exertional and non-exertional.

Exertional heatstroke happens when a dog is exercising in a climate that is too hot and they are not accustomed to these temperatures. However, if the dog has been acclimatized to the conditions prior to sun exposure, they will be less susceptible to heatstroke.

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Non-exertional heatstroke is caused by the dog’s inability to lower its body temperature due to a lack of airflow. This is likely to occur in an enclosed space with no shade or ventilation, for instance, a conservatory or locked car.

Even in the UK, the temperature can hit excruciating highs (especially when there’s no ventilation), so it is vital to be aware of the warning signs and prevention tips to keep your dog safe in the summer.


  • Severe panting

  • Raised temperature (40.5°C or above)

  • Drooling

  • Dehydration

  • Struggling to breath

  • Drowsy and lethargic

  • Vomiting

  • Diarrhoea

  • Increased heartbeat

  • Blood in urine

  • Red, dark coloured gums

  • Staggering and collapsing


Detection and speed are key. Keeping a thermometer in your house constantly is an efficient way to indicate if your dog could have heatstroke. However, if you don’t have access to a thermometer but you do recognise any of the symptoms detailed above, it is essential that you call your vet immediately.

Depending on the severity of the heatstroke, the vet may put your dog on a drip to replace lost fluids and minerals. It is likely that the vet will give you some guidance on how to help your dog’s condition before arriving at the vet, such as:

  • Keep your dog in a cool, shaded area

  • Pour cool water on your dog, but check it is not freezing cold so they don’t get shocked (a cool wet towel might be a good idea)

  • Allow your dog to drink small amounts of cool water if they're conscious and alert enough


Our dogs do not have the same tolerance to intense and extended heat as we humans do. We have sweat glands all over our entire body to help cool us down, dogs only have them in their paws and noses. So, if you feel warm, your dog will be a lot warmer!

Certain types of dogs are more susceptible to getting heatstroke, for instance, obese dogs, dogs with thicker fur and brachycephalic (flat-faced) dog breeds. Despite this, any dog can be subject to heatstroke, so it is important to be aware of how to prevent it and ensure your dog is cool in the summer.

  • Keep your dog shaded and ventilated

  • Do not ever leave your dog trapped in a hot room such as conservatory or hot car

  • Provide your dog with a cool, damp towel

  • Getting a cooling vest/suit for when they are outside

  • Keep track of your dog's water intake, ensure they are staying hydrated

  • Set up a doggie paddling pool if you are going to be in the garden

  • Take your dog for a walk in the morning or later on in the evening – avoid prime sunshine hours

Being out in the sun all day can be tempting, but make sure you take all the precautions to avoid your furry friend catching heatstroke. Investing in items such as paddling pools and cooling vests help to regulate body temperature, but they should not be relied on. Limiting your dog’s sun exposure full stop is the optimal and safest way to prevent heatstroke. Even if the weather does not feel that warm to you, it might do for your dog. After all, they do wear a thick furry coat 24/7!

  1. Pathophysiology of heatstroke in dogs Temperature: Medical Physiology and Beyond, 4, (4), October 2017, 356-370, doi:10.1080/23328940.2017.1367457
  2. Incidence and risk factors for heat-related illness (heatstroke) in UK dogs under primary veterinary care in 2016 Scientific Reports, 10, 2020, doi.org/10.1038/s41598-020-66015-8