- This article has been reviewed by a pet health professional. It is not a substitute for professional veterinary advice.
Heatstroke can affect dogs when their internal body temperature rises dangerously high. Heatstroke in dogs is a life-threatening condition that requires immediate vet attention.
A body temperature above 40.5°Celsius in a previously healthy dog is a major sign of heatstroke, according to Dr. Courtney Pierce, a small animal general practitioner.
“Other signs include heavy panting, dry red gums, excessive drooling, and skin that is hot to the touch,” Dr. Pierce adds. “In the most severe cases, dogs may become unsteady on their feet or even collapse.”
Read on to learn about heatstroke in dogs, what you can do to help, and how to prevent it.
Critical Signs of Heatstroke in Dogs
Unlike people, dogs can’t sweat to cool off when they get hot, Dr. Pierce explains. Instead, dogs keep cool by panting and radiating heat from their bodies through vasodilation, which is the expansion of blood vessels near the skin’s surface.
When a dog can no longer cool themselves off and their core body temperature rises above 40.5°Celsius, their central nervous system can start to shut down. This can cause death without immediate treatment.
The signs of central nervous system dysfunction include:
- Seizures
- Sudden collapse
- Coma
- Lack of response or seeming dazed
- Stumbling and general loss of coordination
These are signs of a medical emergency. You’ll want to get your dog urgent vet attention. If you can’t reach your vet quickly, take them to the emergency vet.
Early signs of overheating
Dogs will show early signs of overheating, according to Dr. Rebecca Greenstein from Rover’s Pet People Panel. These signs include:
- Heavy panting
- Difficulty breathing
- Lethargy
- Vomiting
- Diarrhoea
- A deep red or purple tongue or gums
- Excessive drooling
Tip: Check your dog’s mouth. Excessive drooling and bright red gums mean your dog is working extra hard to remove heat from their body. You can help cool them off using the tips below.
Heatstroke First Aid for Dogs
If you suspect your dog may have heatstroke, you must get them to an emergency vet or animal hospital as soon as possible to save their life.
Once their internal body temperature has risen into the critical range, they will need immediate medical attention to slow down or stop any organ failure that may have already begun.
What to do
In addition to seeking emergency vet care, Dr. Pierce also advises pet parents to start cooling measures immediately by:
- Stopping the activity or exercise that led to the increase in body temperature
- Moving the dog to a cool, shady location
- Applying cool (not cold) water to the dog’s fur
- Using a fan or air conditioning to blow cool air over the dog
Additionally, if you have a dog thermometer, you can monitor your dog’s rectal temperature and tell the vet the highest reading you recorded.
What not to do
- Avoid using ice or ice-cold water to cool your dog down. This causes the blood vessels in the skin to constrict and traps heat in the body’s core.
- Don’t force your dog to drink, since this can cause added stress. Instead, place a bowl of fresh, cool water next to them so they know it’s available.
- Don’t leave your dog unattended for any period of time.
- Don’t take a “wait-and-see” approach. Heatstroke in dogs is a medical emergency.
Once you get your dog to the vet, the health care team will take over with more intense therapies as needed.
How To Prevent Heatstroke in Dogs
Heatstroke is easily preventable if you learn to recognise the early signs of overheating. Once you know the signs, you can take action to cool your dog down before their temperature gets too high.
Here are some important heatstroke prevention tips:
- Never leave your dog in a parked car, even with the windows open or cracked. “When it’s only 75 degrees out, temperatures inside a parked car can easily go above 100 degrees within minutes—even with the windows open,” Dr. Greenstein explains.
- Keep pets indoors when there’s a heat advisory. Heat advisories for people apply to pets, too!
- “Avoid walking dogs during the hottest parts of the day. Pet parents should prioritise early morning and late evening walks,” Dr. Pierce says.
- Pay attention to how the humidity affects the heat index in your area. The heat index is the combined impact of both temperature and humidity and can give you a better idea of what the outside temperature actually feels like.
- Check the pavement before walking your dog by placing your hand or bare foot on it for several seconds. “If it feels too hot for a person, it’s too hot for the dog,” Dr. Pierce says.
- Make sure your dog always has access to fresh, clean water so they can stay hydrated.
- Know your dog’s risk factors. For example, if they’ve entered their senior years or have developed an illness, take extra care when exercising them in the heat.
Tip: Can’t change your usual walking schedule to beat the heat? A pet sitter can help! Explore Rover’s pet care services, from dog walking to dog boarding.
Causes of Heatstroke in Dogs
The main causes of a dog’s internal temperature rising too high include:
- The environment: Exposure to prolonged high temperatures without the ability to find shade or a cool area can leave dogs vulnerable to heat stroke.
- Exercise: One study that reviewed vet records of over 900,000 dogs found that 74% of the dogs had overheated due to exercise.
- Vehicle confinement: Dogs can quickly overheat when left in cars on hot days—even cars with open windows.
Diagnosis
To diagnose heatstroke, a vet will perform a physical examination and analyze your dog’s blood work for organ failure. They will also ask if the dog has had heatstroke before and check for the common clinical signs of heatstroke.
They may also check your dog’s:
- Blood pressure
- Heart rhythm through an electrocardiogram (ECG)
- Sugar levels
- Electrolyte levels
- Blood clotting times
Risk Factors for Heatstroke in Dogs
Several different factors can increase a dog’s risk of developing heatstroke.
Environment
The outside temperature or humidity can significantly increase the risk of your dog developing heatstroke.
“Temperatures above 32.2°C are generally considered the cutoff for walking dogs safely outside,” Dr. Pierce explains.
A dog can also overheat if left in the car on a sunny day.
“As a rule, dogs should not be left in a car if the temperature is above 21.1°C, but this can vary depending on many factors, including the level of humidity and time of day,” Dr. Pierce explains.
Generally speaking, it’s best to avoid leaving your dog in the car at all.
Exercise
Exercising in extreme heat can have a number of negative consequences for dogs, including paw pad burns, heat stress, heatstroke or even death, Dr. Pierce says.
The same study mentioned above even found that dogs are just as likely to die from heatstroke caused by exercise as from heatstroke caused by a hot car.
On hot days, keep your dog inside and try indoor activities for mental stimulation instead.
Breed
Dogs with a restricted airway, such as brachycephalic breeds, have a higher risk of developing heatstroke.
“For brachycephalic breeds, clinical signs of heatstroke can occur when the outside temperature and humidity are only moderately elevated,” Dr. Pierce says.
Flat-faced dogs with a higher risk include:
Talk to your vet about safe temperatures to walk these breeds before taking them out on a warm day. You’ll also want to make sure to provide cool and shady resting spaces inside your home.
Additionally, dogs with thick coats like Siberian Huskies and Alaskan Malamutes can also overheat during hot weather due to their insulating coats.
Important: Dogs use their coats to cool down in hot weather, so you should never shave your dog. This can actually increase their risk of overheating.
Underlying health concerns
Dogs who have already experienced heatstroke or heat stress have a higher risk of developing heatstroke again.
Overweight and obese dogs also have a much higher risk of developing heatstroke. Excess body fat acts as insulation, trapping heat and making it harder for the dog to cool off.
Additionally, Dr. Pierce says dogs who have diabetes and hypothyroidism may also have a higher risk of developing heat-related illnesses.
Age
Your dog’s age can also have an impact on their risk of developing heatstroke.
“Very young dogs and very old dogs may have more trouble regulating their body temperatures,” Dr. Pierce explains.
Medical Treatment for Heatstroke in Dogs
Getting your dog immediate medical attention to treat heatstroke is crucial for their survival.
Some treatments you can expect include:
- IV fluids
- Electrolytes and sugar
- Oxygen
- Fresh frozen plasma
- Anti-seizure medications
Tip: Don’t forget to keep cooling your dog down while driving to the vet. Keep them in front of the car’s air conditioning as you drive.
Outlook for Dog Heatstroke Recovery
Survival rates for dogs who have experienced heatstroke depend on how high their body temperature got and the length of time it stayed elevated.
If you work to quickly cool your dog off and get them immediate medical attention, they will have a much better chance of survival.
However, even with quick treatment, the survival rate for heatstroke in dogs is only about 50%. That’s what makes it so important to prevent this condition in the first place by helping your dog stay cool on hot summer days.
