Emergency Response for Dog Heatstroke

ImmunitySymptomsMeongsiljang Veterinary Advisory Board

We’ve outlined the stage-by-stage symptoms of heatstroke in dogs, along with on-site first aid, veterinary treatment, high-risk breeds, and summer prevention tips.

How Dangerous Is Dog Heatstroke?

A dog panting heavily in hot weather and showing early signs of heatstroke

Heatstroke in dogs is a medical emergency that can lead to organ damage when body temperature rises above 41°C. The most critical step is to begin lowering your dog’s temperature as soon as symptoms appear. If you notice excessive panting, red gums, or stumbling, start emergency first aid immediately and head to the vet. Delaying treatment can result in multi-organ failure, so time is of the essence.

Stages of Heatstroke Progression

Heatstroke represents the most severe stage in the progressive continuum of heat-related illnesses. The following classifications serve as general clinical reference points and may vary depending on individual conditions.

Stage	Classification	Key Symptoms
Heat Exhaustion (Early)	Onset of elevated body temperature	Uncontrolled excessive panting, weakness, restlessness, drooling
Progression to Heatstroke	Body temperature above 41°C	Vomiting, diarrhea, collapse, rapid breathing
Severe Heatstroke	Sustained body temperature above 41°C	Seizures, decreased consciousness, bleeding tendencies, multi-organ dysfunction

Once heat exhaustion progresses to heatstroke, central nervous system abnormalities and organ damage can begin, making rapid early intervention critical.

Heatstroke Key Symptoms Checklist

If you notice any of the following symptoms, suspect heatstroke:

Excessive panting: Persistent, rapid, and labored breathing that is much more intense than usual

Darkened gums: Gums turn bright red or deep crimson

Excessive drooling: Dripping thick saliva in greater amounts than normal

Vomiting and diarrhea: In severe cases, vomit may contain blood or stools may be bloody

Staggering: Unsteady gait with difficulty maintaining balance

Decreased consciousness: Unresponsive to calls or appearing limp and lethargic

A veterinarian checks the gum condition of a puppy suspected of heatstroke.

Go to the Hospital Immediately If You See These Symptoms

If you notice seizures, loss of consciousness, blood in the stool or urine, or pale or bluish gums, take your pet to the nearest emergency animal hospital immediately. During transport, help lower their body temperature by wrapping a damp towel around their neck and armpits. Recommended cooling methods include sponging with lukewarm water and promoting evaporative cooling with airflow; avoid using ice-cold water, as it can be counterproductive.

Causes of Heatstroke

Heatstroke is broadly categorized into two types.

Exertional heatstroke: This occurs when a dog exercises or walks excessively in hot, humid weather. It is especially dangerous for active dogs that get easily excited.

Non-exertional heatstroke: This happens when a dog is trapped in an enclosed car or a poorly ventilated space. The temperature inside a car can rise significantly higher than the outside temperature in a very short time.

Dogs that are overweight, or have laryngeal paralysis or respiratory (airway) diseases, have a harder time regulating their body temperature and are at higher risk of heatstroke. Dogs with thick undercoats also struggle to dissipate heat and require extra care.

On-Site Emergency First Aid

If you suspect heatstroke, begin emergency first aid immediately by following these steps:

Step 1 — Move to a shaded area: Immediately move your pet to a cool indoor space or a shaded area.

Step 2 — Apply lukewarm water: Dampen the neck, armpits, and groin with lukewarm water (around room temperature). Using lukewarm water is recommended over ice-cold water, which can be too extreme.

Step 3 — Air circulation: Direct a fan toward the dampened areas to promote evaporative cooling.

Step 4 — Offer small amounts of water: If your pet is conscious, provide small amounts of cool water.

Step 5 — Seek immediate veterinary care: Transport your pet to a veterinary clinic immediately, even while performing first aid.

A pet owner providing emergency care to their dog with a wet towel in the shade

Treatment at the Hospital

At the hospital, treatment focuses on stabilizing body temperature and organ function.

Intravenous Fluid Therapy: IV fluids help lower body temperature and correct dehydration.

Oxygen Support: Oxygen is administered if breathing is unstable.

Blood Tests: Liver and kidney values, as well as blood clotting function, are checked. Severe heatstroke can lead to clotting disorders.

Intensive Monitoring: Depending on the veterinarian’s assessment, the pet may be hospitalized for an appropriate period to monitor for any organ damage.

The veterinarian will determine the treatment plan and length of hospitalization based on the pet’s condition.

Breeds That Require Special Attention

Brachycephalic breeds (such as Bulldogs, Pugs, and Shih Tzus) have narrow airways, making it difficult for them to regulate their body temperature. Overweight dogs, senior dogs, and large-breed dogs with laryngeal paralysis (such as Labrador Retrievers) are also at high risk for heatstroke. For these dogs, it is safer to limit outdoor activities on hot and humid days and to walk them during the cooler hours of early morning or after sunset.

Summer Heatstroke Prevention Tips

Preventing heatstroke in summer is straightforward, but the consequences of overlooking it can be fatal.

Adjust walk times: Walk your dog before 7 a.m. or after 7 p.m. If the asphalt feels hot when you press the back of your hand against it for five seconds, postpone the walk.

Never leave your dog in a car: Even with windows cracked, temperatures inside a vehicle rise rapidly. Never leave your dog in the car, even for a moment.

Provide plenty of water and shade: Always bring water when going out and ensure your dog can rest in the shade.

Use cooling mats: Help regulate your dog’s body temperature indoors with cooling mats or fans.

A healthy puppy drinking water during an early morning walk

Reviewed by a veterinarian

Dr. Tony — Punnawat Phongkittirak

Veterinarian

A veterinarian who majored in veterinary medicine at Khon Kaen University, Thailand, and completed the IVSA program at North Carolina State University in the United States. Drawing on clinical experience at animal hospitals, he works in the pet healthcare field and is dedicated to building a digital care environment that connects pet parents with veterinarians.

Frequently Asked Questions

Should I immerse my dog in ice water if they have heatstroke?

We recommend using lukewarm water instead of ice-cold water. Wet the neck, armpits, and groin with room-temperature lukewarm water, then expose the pet to a fan to enhance evaporative cooling. Most importantly, begin cooling immediately and transport the pet to a veterinary clinic.

What is a dog’s normal body temperature?

A dog’s normal body temperature ranges from 38.0 to 39.2°C. If it exceeds 39.2°C, close monitoring is advised, and temperatures above 41°C may indicate heatstroke. You can measure your dog’s temperature using an ear thermometer.

Are there any aftereffects if a pet recovers from heatstroke?

Mild cases of heatstroke can be fully reversed with prompt treatment. However, severe heatstroke may lead to lasting complications, such as liver and kidney damage or blood clotting disorders. Even after recovery, it’s important to monitor organ function through regular blood tests as directed by your veterinarian.

What time is it safe to walk your dog in the summer?

It’s safest to walk your dog before 7 a.m. or after 7 p.m. If the asphalt doesn’t feel hot when you press the back of your hand against it for five seconds, it’s okay to go for a walk. However, for brachycephalic breeds or overweight dogs, it’s better to replace outdoor walks with indoor activities on hot and humid days.

Does panting always mean a dog has heatstroke?

Not necessarily. Dogs pant normally to regulate their body temperature. However, if their breathing becomes significantly faster and more labored than usual and doesn't stop, or if their gums turn red or they drool excessively, you should suspect heatstroke.

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References

[1] Drobatz KJ. Heat Stroke. In: Silverstein DC, Hopper K, eds. Small Animal Critical Care Medicine, 3rd Ed. Elsevier, 2023.

[2] Bruchim Y, Kelmer E, Cohen A, et al. Hemostatic abnormalities in dogs with naturally occurring heatstroke. J Vet Emerg Crit Care. 2017;27(3):315-324.

[3] White JD, Kamath R, Nucci R, et al. Evaporative versus iced peritoneal lavage treatment of heatstroke: comparative efficacy in a canine model. Am J Emerg Med. 1993;11(1).

[4] Little S. The Dog Care Handbook: Things I Wish My Vet Had Told Me. 2024.