Heatstroke in Dogs: Signs, Symptoms & How to Prevent It

We love summer. We love the longer days and the improved weather, which together means longer, more enjoyable walks with our pup. Summer is also the perfect excuse to adventure together, whether it’s to visit a dog-friendly beach, a new part of the countryside just on your doorstep or going on a full, week-long vacay.

But, as glorious as the warmer months can be, they come with a few extra responsibilities when you’re a dog parent. Just like us, dogs can feel the effects of the heat and sometimes, it can go from being “a bit too warm” to dangerous pretty quickly. This is heatstroke, something many pet owners don’t realise can affect their dogs, and surprisingly easy too.

This definitely doesn’t mean you have to cancel all your summer fun. It just means a bit of awareness, and maybe a few cool-down breaks, frozen treats and lots of water, so you can keep your precious pup safe and happy when the sun’s blazing.

So, before you grab the lead and head out on your next sunny stroll, let’s chat about how heatstroke in dogs happens, what signs to look out for, and most importantly, how to prevent it.

Yes, dogs can absolutely get heatstroke. In fact, they’re often more at risk than humans. While we can sweat to cool down, dogs don’t have that luxury. They regulate their body temperature mostly through panting and a little bit through their paw pads, which just isn’t as efficient when the heat ramps up.

When a dog gets too hot and their body can't cool down fast enough, their internal temperature can rise to dangerous levels. That’s when heatstroke can set in. It’s essentially the body overheating, and in dogs, it can happen much quicker than many people realise, especially on warm or humid days.

Dogs are also less likely to stop and consciously think, “I’m hot, I better calm down and chill out.” Instead, they’ll often get caught up with the excitement of being out and about and continue running and playing, even if they’re starting to struggle.

Certain breeds, especially those with short noses like Pugs, Bulldogs, and Frenchies, are even more at risk because their breathing is less efficient, making it harder for them to cool themselves down.

It’s not just about direct sun or heat either. Dogs can overheat in cars, on long walks, or even indoors if it’s stuffy with no ventilation. Puppies, older dogs, and those with underlying health conditions are particularly vulnerable too.

So while we might associate heatstroke with sweltering temperatures or tropical holidays, it’s something that can absolutely affect our dogs right here at home on a seemingly “nice day.” That’s why it’s so important to understand the risks, be aware of your dog’s limits and know how to keep them safe and cool when the temperature rises.

When it comes to heatstroke in dogs, the earlier you can spot the signs, the better. Some symptoms might seem mild at first, but they can escalate quickly and that’s where it gets dangerous. Below are the most common symptoms of heatstroke in dogs, along with an explanation of what’s actually happening in their body during each stage.

Excessive Panting

Panting is a dog’s main way of cooling down; it’s basically their version of sweating. But when your dog starts panting hard, fast, and non-stop, it’s often the first warning sign that they’re overheating.

As your dog pants, moisture from their tongue and airway evaporates, which helps release heat from their body. But when the temperature is too high, or your dog is already too warm, this system becomes less effective. They start panting more rapidly in an attempt to bring their body temperature down, but the hotter the air, the less relief panting provides. This leads to a dangerous feedback loop where they keep overheating even while trying to cool down.

Drooling More Than Usual

Increased drooling often goes hand in hand with heavy panting. As dogs work overtime to cool themselves, they produce more saliva, which helps with the evaporation process. However, thick, sticky drool, especially if it’s more than usual, can signal that your dog is struggling to regulate their body temperature.

What’s happening is that the moisture they’re producing isn’t evaporating fast enough, and the saliva itself may start to thicken as they get dehydrated. If your pup’s normally dry-mouthed or a light drooler, and suddenly they’re dripping like a tap, it’s time to take it seriously.

Bright Red or Pale Gums and Tongue

Checking your dog’s gums can give you a surprisingly accurate peek into what’s going on inside their body. In cases of heatstroke in dogs, the gums might look unusually bright red at first. This is due to the blood vessels expanding (a process called vasodilation) to try and dump heat away from the body’s core and push it toward the skin’s surface.

But as the condition worsens, those gums can turn pale or even bluish. This is a worrying sign that the body is struggling to circulate oxygen and blood effectively. When organs and tissues start being deprived of oxygen, things become critical very quickly. So if you notice any change in gum colour, especially paired with other symptoms, it’s an instant red flag.

Lethargy or Weakness

It’s not unusual with heatstroke in dogs to see your pup zooming across the park one minute and then lying down and refusing to move the next. That sudden slump in energy can be more than just tiredness. Lethargy, wobbliness and confusion is a big sign their body is overheating and starting to shut down non-essential systems to protect the core organs.

Basically, when your dog gets too hot, the brain redirects energy away from things like play or movement and focuses on survival, which includes trying to keep the heart, lungs, and brain oxygenated. This can leave your dog feeling drained and dizzy.

Vomiting or Diarrhoea

Another sign of heatstroke in dogs includes vomiting and/or diarrhoea. And in severe cases, their stool and sick may even contain traces of blood. This happens because the heat affects the digestive system, reducing blood flow to the stomach and intestines, which can lead to inflammation, tissue damage, and even internal bleeding.

The body is essentially in crisis mode, and organs that aren’t immediately needed for survival, like the gut, suffer first. So if your dog suddenly starts vomiting after being in the heat, it’s likely more than an upset tummy but a warning.

Staggering, Disorientation or Collapse

This is when things have reached an emergency level. If your dog seems dazed, can’t walk straight, or collapses altogether, their brain is starting to struggle from the lack of oxygen and rising internal temperature. The brain is very sensitive to heat, and once it’s affected, you’re looking at serious consequences including seizures or coma.

Your dog might seem confused, bump into things, walk in circles, or simply lie down and be unable or unwilling to get up. At this stage, urgent vet attention is critical.

Seizures or Unresponsiveness

Seizures, twitching, or your dog becoming unresponsive are the most extreme signs of heatstroke and usually indicate that their body temperature is dangerously high, usually above 41°C. At this point, internal organs like the brain, kidneys, liver, and heart are starting to fail due to the heat.

This is a full-blown medical emergency. Without immediate cooling and veterinary care, heatstroke at this stage can quickly become fatal.

We know this all sounds scary, and most of the time, when you’re keyed up on heatstroke in dogs, it won’t ever get as far as seizures of collapse. That’s because if your pup does ever suffer from heatstroke, even mild, you’ll know exactly what to do so things don’t get worse.

If you suspect your dog is suffering from heatstroke, it’s really important to act fast. Time matters, so the sooner you intervene, the better the outcome. Let’s break it down into the right steps to take depending on how serious things look.

Mild Symptoms: Panting, Drooling, Sluggishness

If your dog seems a little “off” and they’re panting harder than usual, drooling more, maybe a bit tired or slower on their feet, they may be in the early stages of heat exhaustion.

In this instance, get them into the shade or indoors, preferably somewhere cool and well-ventilated. A fan or air conditioning can help a lot. Make sure to immediately offer cool, but not ice-cold, water and encourage them to drink little sips. But don’t force it.

You can also use a damp towel or sponge to gently wet their paws, belly, chest, and inside of their legs. These areas have blood vessels closer to the surface and help cool the body quicker. Again, avoid using freezing cold water, as it can actually cause blood vessels to constrict, trapping heat inside the body.

Then let them rest, and keep a close eye on their breathing and energy levels for any changes. If they perk up within 10 to 15 minutes, that’s a good sign. But still keep things calm for the rest of the day. That means no more exercise or excitement until they’ve fully recovered.

Moderate Symptoms: Bright Red Gums, Vomiting, Weakness

If your dog’s showing signs like vivid red gums, unsteady movement, vomiting, or lying down and struggling to get back up, this is more serious, and you should treat it as an urgent situation.

Start cooling immediately, as described above by using shade, airflow and damp towels. Again, do not put them in ice water. It’s tempting, but extreme cold can shock their system and make things worse.

Then you should call your vet and let them know you’re coming. Tell them your dog’s symptoms so they can prepare. Try your best to continue to cool your dog during transport, whether that’s opening the car windows, cranking up the AC and applying damp towels on route. When you arrive at the vets, they’ll know what to do.

Severe Symptoms: Collapse, Seizures, Pale Gums, Unresponsive

This is a full-on emergency. If your dog collapses, has a seizure, goes unresponsive, or shows pale/blue gums, they are in critical condition and need veterinary help immediately.

Don’t delay and call your vet or nearest emergency clinic right away. Cool them down while you wait for help or prepare to transport them, but be gentle and calm. Focus on cooling their paw pads, armpits, and groin area and keep air flowing around them by opening windows and using fans.

Don’t force water into their mouth if they’re unconscious or can’t swallow as this can cause choking.

Once they’re at the vet, they may need IV fluids, oxygen support, and blood tests to check for organ damage. It can be scary but catching it quickly and getting help gives them the best chance of a full recovery.

Thankfully, heatstroke in dogs is totally preventable when you know what to look for and how to add some common-sense swaps into your usual routine. Here’s how to keep your pup cool and healthy when the sun gets stronger…

Keep Them Hydrated 

This one’s simple but so important: make sure your dog always has access to fresh, clean water. That means indoors, outdoors, on walks, in the car… everywhere. When it’s hot, dogs can dehydrate quickly, especially if they’re panting more than usual. If you're heading out, bring a portable water bottle and bowl with you, and encourage them to drink often.

Avoid Walking During Peak Heat

This is another essential tip for avoiding heatstroke in dogs. Skip the midday walks aka the hottest part of the day, usually between 11am and 4pm, as this is when your dog is most at risk. Instead, aim for early morning or late evening strolls when the ground is cooler and the sun isn’t beating down.

Hot pavements can actually burn your dog’s paw pads, and even short bursts of exercise in high heat can lead to heat exhaustion. Always do the “back of the hand test” too, so if you can’t hold your hand on the pavement for 5 seconds, then your dog can’t be expected to place their delicate paws on there either.

Stay Inside When It’s Too Hot

When it’s really hot, don’t feel guilty about skipping the walks entirely. We promise, even despite those puppy eyes, your dog won’t mind. Most dogs are perfectly content chilling indoors, especially if they’ve got a cool, well-ventilated space to relax in.

Pop a fan on, close the curtains to block out direct sun, and offer enrichment toys like lick mats or treat dispensers to keep them mentally stimulated without the physical effort. Remember, boredom doesn’t cause heatstroke, overheating does.

Watch for Sudden Temperature Changes

Ever headed out on a walk and suddenly felt the heat rise out of nowhere? It happens. Clouds move, shade disappears, and suddenly you’re in full sun. If this happens while you’re out with your dog, don’t push through. Find shade immediately, take a break, and offer them water.

Keep an eye on their behaviour, if they start slowing down, panting more, or refusing to walk, don’t try to encourage them to just keep going. Instead, turn around, get someone to come collect you or rest until they’re ready to move safely.

Use Cooling Dog Mats & Frozen Treats

There are loads of handy products that can help prevent heatstroke in dogs, from dog cooling mats and vests to frozen treats and ice-packed toys. You can even soak a bandana in cold water and tie it loosely around your dog’s neck for a quick DIY cool-down.

Frozen fruit like blueberries or watermelon, low-sodium broth ice cubes, or lick mats smeared with dog-safe paste and frozen are fun ways to help them regulate their temp while keeping them entertained when walks aren’t possible

We know the topic of heatstroke in dogs isn’t an easy one to read about. The possible symptoms they can get and the danger involved is enough to over-worry any pup parent. But the fact that you’re here, learning about everything you need to know about spotting, treating and preventing heatstroke in dogs, just shows what a truly good pup parent you are.

And this doesn’t mean you can’t still enjoy the summer with your dog. It just means you need to keep an eye on the temperature, adjust your routine a little when it’s warmer than normal and stay in tune with your dog’s behaviour so you can quickly spot anything out of the ordinary.

If you ever spot signs of heatstroke in dogs, no matter how mild or severe, don’t take any chances. It’s always best to consult your vet and the earlier you act, the better the outcome.

And when it comes to keeping them cool and entertained indoors, WOOOF has you covered. From cooling mats and frozen treats to lick mats, enrichment toys and everything in between, we’ve got all the tools you need for a safe and fun summer.

All advice sourced from RSPCA and PDSA

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