Dog heatstroke first aid

1. Stop the heat. Stop exercise, move your dog into shade or a cool room, and take it out of any hot vehicle or building (RSPCA). Lay it on a cool floor (Royal Kennel Club).
2. Start cooling at once. Pour or spray cool tap water over the body, or sponge it on if water is short. Belly, armpits and feet are good places to wet (VCA). Keep water away from the nose and mouth so your dog does not breathe it in (PDSA, RSPCA). With a thick coat, soak right down to the skin (US military working dog guideline).
3. Add moving air. Put the wet dog in the path of a fan or the AC (VCA). Moving air speeds the evaporation that carries heat away.
4. Call your vet while you cool. Say “heatstroke” and that you are coming (RSPCA says to call ahead). If someone else is with you, one person cools and the other calls.
5. Go to the vet. Keep the dog wet, in the airflow, on the way. Cornell says to run the car AC on the dog while travelling.
6. Water to drink. If your dog is awake and wants it, offer small amounts (Royal Kennel Club; Merck Veterinary Manual says once the temperature starts to fall). PDSA says not to force a dog to drink.

Why cooling comes before the drive: a working dog's temperature can keep rising for about 15 minutes after exercise stops (US military working dog guideline), and in UK data most heat illness that followed exercise followed an ordinary walk (Hall 2020, Animals). Veterinary guidance is to cool before transport, yet only about one dog in five was cooled before it reached a UK practice, and the authors of that study say the message “cool first, transport second” needs to be communicated more clearly (Hall 2023).

Cooling must not become a reason to delay the vet. The sources do not say how many minutes to cool before leaving. Cool where you are while someone calls the clinic and gets the vehicle ready, then go. That is my reading, so ask your vet what they want you to do.

The sources do not fully agree, so here is exactly what each one says. Where they overlap is ordinary tap water over the body with moving air. I do not tell owners to look for ice.

So ice-cold water is disputed: some sources say any cooler water is fine, others say avoid cold water and ice. I would not take the risk at home, and you do not need ice to cool a dog quickly. Immersion brings its own danger, because a scared dog may panic and one that is weak cannot hold its head up. Never force a dog into water and never leave one alone in water; Hall 2023 says an immersed dog needs constant monitoring with its head supported.

A dog's normal rectal temperature is about 38.6 to 38.9 °C (101.5 to 102 °F) (Merck Veterinary Manual). Cooling is not meant to take it back to normal, because the temperature keeps falling after you stop and over-cooling can follow.

• VCA: stop once the dog shows signs of recovery or its temperature falls to 39.4 °C (103 °F), or it could become too cold.
• US military working dog guideline: cease cooling once the rectal temperature is below 39.4 °C (103 °F), and warm the dog if it falls below 37.8 °C (100 °F). It also says a rectal reading can lag behind the true core temperature by up to 15 minutes.
• Today's Veterinary Practice: stop active cooling at 39.7 to 40 °C (103.5 to 104 °F) to avoid rebound hypothermia.
• Hall 2023: the study gives no stopping temperature.

So the sources give a range of about 39.4 to 40 °C. Most owners cannot take a reliable rectal reading in an emergency, and you should not delay the vet to try. If you have no thermometer, follow VCA's wording: stop when the dog shows signs of recovery, and keep going to the vet.

The VetCompass clinical grading tool sorts UK dogs by signs. It was built from 856 heat-illness events (Hall 2021). The deaths include dogs that were put to sleep.

Gum colour: PDSA lists bright red gums or very pale gums as a moderate sign, and the RSPCA lists red gums and tongue and noisy breathing. The US military guideline lists pale gums among the signs of shock.

Heatstroke is usually defined as a core temperature above 41 °C with brain signs such as dullness or fits (Bruchim 2017). Body temperature was left out of the grading tool because a single reading is a poor guide to how sick a dog is (Hall 2021), and working dogs often reach above 41 °C in exercise without harm (US military working dog guideline). The signs matter more than the number.

• Cool first, then travel. Do not wait for the dog to look better before you set off.
• Use an air-conditioned car if you can. PDSA says an air-conditioned car, or one with the windows open, and to make sure the dog cannot escape.
• Keep the coat wet and in the airflow, as Cornell advises: wet the dog with cool water and run the AC on it while travelling.
• Lay a wet towel under your dog, not over it, and wet it again often (RSPCA).
• Call ahead so the clinic is ready (RSPCA).
• If someone else can drive, they should. One person drives and one keeps the dog wet and in the airflow. That is practical sense rather than something the studies tested.
• If you have no AC vehicle, soak your dog before you leave, keep it in the open air and go. That is my judgement: do not wait for a better vehicle.
• Never leave your dog alone in the vehicle while you do something else. A parked car heats fast: in a test, a dark car rose by about 40 °F on average in an hour and cracked windows did not slow it (McLaren 2005).

• Do not use ice or ice packs. Today’s Veterinary Practice, VCA and the military guideline advise against it, and Merck says not to immerse in cold water. Merck’s owner page does list ice packs, so the sources differ.
• Do not drape a wet towel or blanket over the whole body. It can trap heat (RSPCA, PDSA, VCA, Dogs Trust).
• Do not force water. Do not pour water into the mouth or let it go up the nose, because it can be breathed in (PDSA, RSPCA). If your dog is drowsy, collapsed or fitting, give nothing by mouth. That last part is my judgement, following the same reasoning.
• Do not use rubbing alcohol. VCA says it is no longer recommended, and the military guideline says it is relatively ineffective on the paws.
• Do not force a scared dog into water, and do not leave a dog alone in water (Hall 2023: an immersed dog needs constant monitoring).
• Do not give any medicine. Human medicines such as paracetamol can poison dogs. See human medicines that are dangerous to pets.
• Do not wait and see. Do not stop at cooling. Go to the vet.

Treatment is hospital care, and none of it is for you to copy at home. From Today's Veterinary Practice, the US military working dog guideline and the Hall and Bruchim papers:

• Check awareness, breathing, circulation and temperature first.
• Carry on safe cooling with fans and cool or tepid water, and stop before the dog gets too cold.
• Give fluids into a vein to support the blood pressure. The military guideline says their value in cooling and support cannot be overstated.
• Test the blood for clotting, blood sugar, salts, kidney and liver values, and watch heart rhythm, blood pressure and how much urine the dog makes.
• Treat fits, vomiting and bleeding, and give oxygen if needed.
• Keep the dog in for observation. Multiple organ failure and clotting problems can appear during hospital stay (Today's Veterinary Practice).

There is no single drug that treats the damage heatstroke does to clotting and inflammation, which is why early cooling and supportive care matter so much (Bruchim 2017). PDSA adds that after discharge you should watch your dog for 24 to 48 hours and expect a check-up a few days later.

• Heat can injure the kidneys, liver, gut, blood clotting and brain. Multiple organ failure can develop during the hospital stay (Today's Veterinary Practice), and VCA says some pets have permanent organ damage and may die later from complications.
• In 54 dogs treated at one Israeli teaching hospital, blood-clotting failure (DIC) and kidney failure were linked with death, half of the dogs died, and a delay of more than 90 minutes before admission was linked with death (Bruchim 2006). These dogs came to a teaching hospital, so they may have been sicker than most.
• Even dogs graded mild in the UK data had deaths, about 2 in 100 (Hall 2021).
• A dog that has had heat illness is at greater risk of it again (VCA).

To avoid a next time, read the dog heatstroke risk checker, which explains who is at higher risk and how Kerala's humidity makes a walk riskier.