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The important points, first
- Always take water and a collapsible bowl when you go out with your dog, and offer drinks often.
- Go out in the cooler hours, look for shade and test the asphalt with your hand before walking on it.
- If your dog seeks shade, pants heavily, whines, will not play or drools, move it somewhere cool and ask your veterinarian for advice.
- Drinking too much is dangerous too: water play needs breaks, and at the sea your dog should not drink salt water.
Why water matters more in summer
Dogs have sweat glands only on their paws, and their main way of losing heat is panting; shade, breezes and swimming help too. According to Cornell, heatstroke most often affects dogs left in cars, dogs kept outside in hot, humid weather without shade and dogs exercising in the heat. All dogs are at risk, but some more than others: short-muzzled breeds, overweight or older dogs, dogs with heart or lung conditions and dogs with thick or dark coats.
Fresh water should always be available and offered often. Cornell advises bringing water and a collapsible bowl every time you go out with your dog and giving it plenty of chances to drink. Paddling pools and sprinklers are useful for cooling it down.13
On walks and away from home
The sun is highest around noon, but the hottest hours are in the late afternoon, roughly between 3 and 5 pm. It is better to go out early in the morning or in the evening, on shaded routes. Avoid strenuous activity in the hot hours, on humid days and in early summer, when your dog is not yet used to the heat. In extreme temperatures it is best to stay indoors, ideally with air conditioning or fans.
Asphalt holds a lot of heat and can be much hotter than the air. Cornell suggests placing your hand on it: if you cannot keep it there for about 10 seconds, it is too hot for your dog’s paws too, so walk on grass or change the time. Bring fresh water even if you are heading to a lake or the sea; there are dog water bottles with a bowl attached. Water left in a garden hose can get hot enough to burn. Never leave your dog in a car: cracking the windows does not keep it cool.13
Recognising warning signs
The first signs that a dog is struggling with the heat are seeking shade, heavy panting, whining, restlessness, not wanting to play and drooling; vomiting or diarrhoea can also appear. If it keeps panting and drooling, struggles to breathe, becomes weak or confused, has seizures or collapses, it is heatstroke and the dog needs a veterinary hospital straight away. Cornell points out that if you feel hot, your dog may feel even hotter.
At the first signs, move your dog into shade or air conditioning, offer fresh water and ask your veterinarian for advice. You can wet it with cool water, down to the skin in double-coated breeds, and place it in front of a fan. Do not cool it too quickly, because it risks hypothermia.13
Too much water can be harmful too
A dog that spends the day going in and out of a pool or lake, perhaps chasing balls, can swallow a lot of water without anyone noticing. When too much fresh water is swallowed, the electrolytes in the blood become diluted. This water intoxication can cause a bloated belly, vomiting, diarrhoea, lethargy, weakness and confusion, and in severe cases brain swelling and seizures. Cornell advises frequent half-hour breaks from the water throughout the day.
With seawater the opposite happens: excess salt draws water out of brain cells and can cause tremors, disorientation and seizures. The magnesium in seawater also causes sudden watery diarrhoea. Before going to the beach, make sure your dog has drunk plenty, so it is less tempted to drink salt water, and bring fresh water. Give it breaks between swims and a 20–30 minute walk before getting back in the car. In both cases a veterinarian is needed quickly. Do not let your dog drink standing water, not even from buckets or troughs: it can contain toxic blue-green algae.23
Sources and checks
Numbers in the text lead to the exact source. Commercial blogs and social posts are not used as evidence.
- 1University veterinary centre
Summer heat safety tips for dogs
Cornell University College of Veterinary Medicine · Riney Canine Health Center · Sweat glands only on the paws and cooling by panting, at-risk dogs, heatstroke signs, hottest hours, water and collapsible bowl, about 10-second hand test on asphalt, cars.
Link checked on 16 Sept 2026 - 2University veterinary centre
Summer safety tips
Cornell University College of Veterinary Medicine · Riney Canine Health Center (DogWatch) · Fresh water intoxication with diluted electrolytes, half-hour breaks, saltwater intoxication, drinking before the beach, a walk before the drive home, blue-green algae even in buckets and troughs.
Link checked on 16 Sept 2026 - 3University veterinary centre
Canine Summer Safety Tips: May 2024
Cornell Riney Canine Health Center · Asphalt checked by hand, cold water and bottles with a bowl, scalding water in garden hoses, signs of heat stress, avoiding over-rapid cooling, fresh and saltwater intoxication.
Link checked on 16 Sept 2026
This guide does not recommend amounts of water or treatments. If your dog drinks much more or much less than usual, or shows signs of illness, contact your veterinarian.