Heatstroke in dogs - and how to help prevent it

Heatstroke is a serious illness and can happen fast. A dog develops heatstroke when their core body temperature rises too high for them to be able to lower it. This can cause organ failure and, very sadly, death. That’s why it’s important to understand what it is and how to help prevent it.

A common misconception is that you only have to think about heatstroke during a very hot weather, but this isn’t the case with animals. 

Heatstroke can happen to dogs if they over-exercise in warm weather, have a walk on a hot day, are outside when it’s hot, are left in a warm car or even if they’re in a warm, humid room. Research has revealed that 74.2% of heat-related illness events UK vets saw were triggered by exercise¹.

Remember, dogs not only have their coats on all the time, unlike us they don’t have sweat glands all over their bodies to tackle the heat. This means they can’t regulate their body temperature anywhere near as well as we can.

Dogs rely on panting and external cooling to do the job. That’s easier said than done when you can’t take off your furry coat. 

While any dog can get heatstroke, some dogs are more likely to suffer from heatstroke and heat-related illness. This includes those that have thick coats, brachycephalic (flat-faced) breeds, dogs that are overweight, old dogs, young dogs or those with certain conditions, including heart or lung issues.

This Royal Veterinary College fact file describes the different stages of heatstroke. Some signs include:

Early signs:

1. Rapid panting or breathing, or excessive panting

2. Excessive drooling

3. Bright red tongue and/or gums

4. Vomiting/diarrhoea

Advanced signs:

5. Lethargy, drowsiness

6. Dizziness or staggering

7. Seizures

8. Collapse

As with any dog ailment, prevention is always better than cure, so here are our experts’ top tips to help keep pets cool and safe from the harm of heatstroke.

1. Provide some shade

Whether it’s a trip to the park, a day at the beach or just time spent in the garden, always make sure dogs have access to shade when they’re outdoors in warm weather.   

2. Keep them hydrated

Our dogs should always have ready access to clean drinking water, whatever the time of year – and even more so during summer. Remember, as well as our dogs drinking more in summer, water evaporates faster in warm weather – so bowls will need refilling more regularly. If you’re going to be out and about, a travel bottle and bowl is a great solution to keep dogs hydrated and happy.

3. Let the fresh air in 

Our pets always appreciate a well-ventilated space. This is especially important for dogs as they pant to cool down, so good airflow is crucial and air flowing around them will do a little to help keep them cooler.

4. Never, ever leave a dog or any pet in a hot vehicle or room

Even with the windows open, a car, van or motorhome, conservatory or garden room can quickly become unbearably hot for a pet on a sunny day. Sadly, this can kill pets, so it's extremely important not to leave pets in vehicles. It’s actually a good idea to avoid travelling with pets on hot days if possible if you don’t have air con on in the car.

5. Avoid overexercising in warm weather and hot-weather walkies

We need to avoid exercising our dogs at the warmest times on warm or hot days (usually between 11am and 3pm but check the weather report). Stick to cooler times of day – usually mornings and evenings. 

Avoid walking dogs on surfaces that are too warm – sand, concrete and tarmac can get especially hot and our dog’s poor paws will be exposed to all that heat. If it’s hot to your touch, it’s too hot for them. 

If they need a walk to wee, try walking where there’s shade or water to help with keeping cool.

If you think your dog may be suffering from heatstroke, act fast and follow these first aid steps.

You can find out more about how to give your dog heat stroke first aid on these pdsa and RSPCA pages and on this Royal Veterinary College fact file.

With the right treatment given as soon as possible, dogs can recover fully from heatstroke. But a delay in treatment, or a severe heatstroke, can cause serious harm. Always contact your vet if you suspect your dog has suffered from heatstroke – even if they seem to be recovering. Your vet will be able to give the right treatment for your dog so they have the best chance of getting back to their old self soon.

^1. Hall et al. Dogs Don’t Die Just in Hot Cars—Exertional Heat-Related Illness (Heatstroke) Is a Greater Threat to UK Dogs MDPI, 2020, Vol10, pp 1 -21