Hot weather is riskier for dogs than most owners realise.
Humans cool down by sweating across the whole body. Dogs cannot. They release heat almost entirely by panting, moving air across the tongue, nose and airways, with only a small contribution from sweat glands in the paw pads. When the air is hot, humid, or both, panting becomes far less effective and a dog's core temperature can climb quickly.
A dog's normal body temperature sits between 38.3°C and 39.2°C. Heatstroke, also called heat related illness, begins when the core reaches around 40°C (104°F). Above 41°C, organ damage can start within minutes.
The Royal Veterinary College's landmark 2020 study reframed how vets think about heat risk in dogs. It found that 74 percent of heat related illness cases in UK dogs were triggered by exercise, not hot cars, and that walks on warm days are the single biggest cause. Brachycephalic (flat faced) breeds such as Bulldogs, French Bulldogs, Pugs and Boxers are more than twice as likely to suffer heat related illness as other dogs.
One in seven UK dogs who develop heat related illness die from it, which is why catching the early signs matters so much.
Know the signs
Early signs to watch for: heavy, frantic panting that does not ease with rest, bright red gums and tongue, thick or ropey drool, a dog that slows down or refuses to walk, and wide, glassy eyes.
Emergency signs that need a vet immediately: wobbliness or disorientation, vomiting or diarrhoea, collapse or seizures, and gums turning blue, purple or very pale.
The PDSA and Blue Cross both stress that early intervention is everything. By the time a dog collapses, the window for a good outcome is already closing. If you suspect heatstroke, move your dog into shade, pour cool (not ice cold) water over them, especially the neck, belly and paws, offer small sips of water, and call your vet on the way. Recent research confirms that cooling before transport saves lives.
A few habits worth building
Walk early or late, ideally before 8am or after 8pm in warm weather. If the pavement is too hot for the back of your hand held there for five seconds, it is too hot for paws.
Watch the humidity as well as the temperature. A 22°C humid day can be more dangerous than a 28°C dry one.
Skip the run. Cycling, jogging and ball throwing in the heat are among the highest risk activities in the data.
And always carry water. A dog that will not drink from a bowl when stressed or excited is already behind.
Why hydration matters
Plain water is the foundation, but many dogs simply do not drink enough on hot days, especially when stressed or out on a walk. A well hydrated dog regulates its temperature more effectively and recovers faster from exertion.
How Better Hydration fits in
That is the thinking behind Better Hydration: a functional drink for active dogs made with goat's milk, MCTs, collagen, nutritional yeast, lion's mane and ginseng. Just add water for a drink most dogs will actually finish, even on the days they ignore their bowl.
Sources
1. Hall, E.J., Carter, A.J., & O'Neill, D.G. (2020). Dogs Don't Die Just in Hot Cars: Exertional Heat Related Illness (Heatstroke) Is a Greater Threat to UK Dogs. Scientific Reports, 10, 9128.
2. American Veterinary Medical Association. Hot weather safety for pets.
3. PDSA. Heatstroke in dogs.
4. Blue Cross. Dogs and heatstroke: how to keep your dog safe.
5. Hall, E.J., Carter, A.J., Bradbury, J., Beard, S., Gilbert, S., Barfield, D., & O'Neill, D.G. (2022). Proposing the VetCompass clinical grading tool for heat related illness in dogs. Scientific Reports, 12, 6828.
This article is educational and not a substitute for veterinary advice. If you think your dog is suffering from heatstroke, contact your vet immediately.