Sunny weather makes you want to get out and enjoy it with the whole family, canine best friend included. What’s considerably less fun is a dog with a heat-related illness.
FirstVet vet Dr Rachel Cox looks at what you can do to protect your dog through the hot summer months.

Dogs love spending quality time with their humans, whether that’s a walk or a game of fetch – and summer usually means even more opportunities to get outside together.
The trouble is, plenty of dogs get so caught up in the fun that they don’t know when to stop. Walking a dog in hot weather can quickly become dangerous, particularly without ready access to water or shade.
Heat-related illness in dogs is more common than perhaps a lot of owners realise. VetCompass research from the Royal Veterinary College and Nottingham Trent University, drawing on records from over 900,000 UK dogs, found hundreds of cases a year even before accounting for milder cases that never make it to a vet.
There are several causes of heatstroke, but the most common by far is being left in a hot, enclosed space like a car. It can take as little as 15 minutes for a dog to die of heatstroke in these conditions.
Pets can’t tell you when they’re starting to overheat, which is exactly why it falls to us as owners to recognise the signs ourselves.
Dogs can’t sweat through their skin the way we do, so panting is their main way of regulating temperature. You’ll notice it after exercise, or when they’re excited – which, let’s be honest, is most of the time you walk back into a room.
Constant panting with no let-up, though, can be one of the earliest signs of overheating or overexertion. As such, it’s worth keeping an eye on excessive panting specifically during hot weather.
This one’s usually easier to spot. Falling over, walking in circles, an unsteady gait, or a head tilted to one side can all point to disorientation. And it tends to get worse the longer it’s left.
See to it as soon as you notice it. If your dog isn’t back to their usual self after some shade and water, get them to a vet.
Dry gums that look bright red or purple are another warning sign. As oxygen levels drop further, gums can turn blue – a clear signal your dog is overheating and needs urgent veterinary attention.
Collapse is a serious sign of heatstroke on its own, and more so alongside any of the others here. If your dog collapses, get them to a vet immediately.
Both are common dog complaints generally, but alongside other signs of heatstroke, they mean it’s time to act fast – start cooling your dog and contact your vet.
Plenty of things can make a dog anxious – new people, unfamiliar animals, a missing family member… But in hot weather, this kind of distress can also be a sign they’re struggling with the heat.
A dog who won’t budge, or is clearly trying to avoid the sun, may already be showing signs of heatstroke. Resting in the shade is often a coping mechanism for a dog who’s struggling to cool down.
Context matters here, much like with anxious behaviour. A bit of drool at the sight of a favourite treat is normal; excessive drooling on a hot day is more of a concern.
The same goes for thirst – a dog who’s thirsty after a long walk is normal, but continuous drinking that never seems satisfied can point to overheating.
Slower reactions, not responding to commands, or a glassy look in the eyes are more serious signs of heatstroke, and worth acting on quickly.
These are the most severe signs, with the highest risk to your dog’s health. If you see any of these, get them to your nearest vet or an emergency vet straight away.
Vets increasingly think of heat-related illness as a progressive condition, rather than something that’s simply present or absent. VetCompass researchers have proposed three broad stages, which can help make sense of how quickly things can escalate:
The earlier you catch and act on the mild signs, the less likely things are to progress towards the severe end of the scale.

No one wants to see their dog suffer, and there’s plenty you can do at home in the earlier stages of overheating. If your dog’s showing any of the signs above, current veterinary advice – endorsed by the Royal Veterinary College – can be summed up as ‘cool first, transport second’:
Yes – a hot, stuffy house can be just as risky as a hot car. Keeping an eye on your home’s temperature during a heatwave helps keep your dog safe. A few ways to maintain a cooler home:
Every dog reacts differently to heat. Puppies, small dogs, dogs carrying extra weight, heavier-coated breeds, and dogs with existing health conditions can all be more vulnerable. It’s worth understanding your own dog’s individual tolerance rather than assuming they’ll cope the same as any other dog.
If you see a dog in visible distress in a hot car, call 999 immediately and ask for the police. The RSPCA doesn’t have the legal power to break into a vehicle – only the police do. As such, calling their cruelty line first can waste valuable time in an emergency. Every minute matters here.
If the dog doesn’t appear to be in immediate distress but you’re still concerned, the RSPCA recommends the following:
If the owner does return but you still feel the dog was put at genuine risk, you can still report it to the police afterwards.

Some breeds are considerably more vulnerable to heat than others. Large-scale VetCompass research has consistently found brachycephalic (flat-faced) breeds and dogs over 50kg among those at greatest risk of heat-related illness. Breeds worth being especially mindful of include:
If your dog falls into one of these categories, it’s worth being extra cautious with exercise timing and intensity once the weather warms up. Go for shorter, gentler walks in the cooler parts of the day, rather than a full walk when it’s too toasty.
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