Heat Stroke in Dogs: Signs and What to Do Right Now

What to do right now

Step 1: Phone your vet or an emergency clinic so the team can get ready for you, and if someone else is with you, have one person drive while the other keeps cooling. Step 2: Move your dog out of the heat, ideally into an air-conditioned room or car, or at least into deep shade with moving air. Step 3: Pour or sponge cool or lukewarm water over the belly, armpits, paws and head, where the coat is thinnest and heat escapes fastest.

Step 4: Set your dog in front of a fan, or run the car air on high, so the water evaporates and carries heat away. Step 5: If your dog is alert, offer room-temperature water, but never pour water into the mouth of a drowsy dog. Step 6: Keep wetting your dog on the drive.

What not to do

Do not use ice, ice packs or ice-cold water. VCA Animal Hospitals says ice and rubbing alcohol are no longer recommended, and the AKC warns that very cold water can tip a dog into shock and make things worse. Cool is the goal, not cold, because the body needs to keep blood flowing to the skin to shed heat.

Do not drape a soaked towel over your dog and leave it there, because a covering traps heat against the body. Wet the skin directly, keep air moving, and do not wait at home to see whether it passes.

Early and late signs of heat stroke

Early signs listed by the AKC include heavy panting, fast breathing, heavy drooling, bright red gums and tongue, hot skin, a racing heart, dry or sticky gums, sudden restlessness and wobbling. A dog at this stage may still walk and respond to you, which is exactly why owners wait. Do not wait.

Late signs mean the body is starting to fail. Watch for pale or bluish gums, dilated pupils, muscle tremors, collapse, seizures, uncontrolled peeing or pooping, and vomiting or bloody diarrhea, which the ASPCA lists among the signs of overheating. A dog that will not move, cannot stand or stops responding needs to be on the way to an emergency vet within minutes.

The temperatures that matter

A dog's normal resting temperature is about 99 to 102.5°F, according to the AKC. VCA considers anything above 103°F abnormal, the AKC describes heat stress above 104°F, and it puts heatstroke above 105.8°F. VCA notes that multiple organ failure and death become likely at around 107 to 109°F, which is why the clock matters so much.

If you have a rectal thermometer, a reading helps your vet, but never let it delay the drive. Vets usually stop cooling at about 103°F, because going lower can cause hypothermia, which is why home cooling is first aid and not treatment.

Which dogs are most at risk

Flat-faced breeds such as Pugs, Bulldogs and Boston Terriers pant less efficiently and can overheat even in moderate weather. Puppies, senior dogs, overweight dogs and dogs with heart disease, breathing problems or laryngeal paralysis are also more vulnerable, as are muzzled dogs, whose panting is restricted. VCA names a parked car with poor ventilation as the most common cause.

Humidity makes it worse, because panting relies on evaporation. Hard exercise on warm days, a yard without shade or water, and a hot garage all raise the risk, and VCA notes that a dog who has had heat stroke once is more likely to have it again.

What the vet will likely do, and preventing it next time

Your vet will usually continue controlled cooling, give intravenous fluids and oxygen, and monitor temperature. Blood tests check the kidneys, liver and clotting, because heat damage can appear hours later, so many dogs stay in the hospital for monitoring.

To prevent a repeat, never leave your dog in a parked car, walk early in the morning or in the evening, give constant access to shade and fresh water, and cut exercise short on hot or humid days.

This page is general information, not veterinary advice, and it cannot replace an examination by the vet who knows your pet.