Overheating in Dogs

Holiday & seasonal
Poster displaying facts of canine heat stroke with a cattle dog sitting in front of a fence

Hot weather spells trouble for dogs because heat and humidity can quickly raise a dog's body temperature to dangerous, life-threatening levels.

While heat-related illnesses are among the most common summer canine ailments, they need not be. Armed with a basic understanding of how and why dogs overheat, as well as a good dose of common sense, you can keep your dog safe as summer temperatures sizzle.

Body Basics: How Dogs Regulate Body Temperature

A dog's average body temperature is 101.5° F (38.6° C), with a normal range between 100° and 102° (37° C and 39° C). While temperatures can vary throughout a dog’s body, the core temperature is what a dog’s body uses to maintain constant internal conditions, also known as homeostatic condition, and includes blood pressure, blood chemistry, and body temperature.

Unlike humans, dogs don't sweat (except to a minor degree through their foot pads) so they don't tolerate high temperatures as well as humans do. A dog's primary cooling mechanisms is panting, which exchanges warm air for cool air. However, when air temperatures are close to a dog's body temperature, cooling by panting is not an efficient process. 

What causes dogs to overheat?

When a dog’s normal body mechanisms can't keep their temperature within a safe range, heat induced illnesses occur. Heat exhaustion, heat prostration, and heat stroke are increasingly severe levels of the same basic condition. While the first two are serious and can take a serious toll on a dog's health, heat stroke kills dogs.

Dogs with moderate heat stroke (a body temperature of 104°) can recover if given prompt first aid and veterinary care. Severe heat stroke occurs when a dog’s body temperatures is over 106° F (41° C) and is considered a life-threatening medical emergency.

Heat stroke is usually caused by high environmental temperatures, but can be precipitated by several factors, both external and internal within the pet themselves. Causes are usually divided into two categories: those that decrease the pet’s ability to disperse excess body heat, and those which increase body temperature.

A poorly ventilated space, sudden exposure to high temperatures, high humidity, and limited water access are all factors that may increase your pet’s chance for heat stroke.

Dogs at Higher Risk of Overheating and Heat Stroke

Some dogs are at a higher risk of developing heat stroke including:

  • Brachycephalic dogs

  • Older dogs

  • Puppies

  • Sick dogs – including those with underlying heart and lung diseases

  • Obese dogs

  • Dogs not acclimated to hot weather

  • Dogs with a prior history of heat-related disease

Other factors that increase your dog’s chance for overheating include thick hair coats or jackets and extensive periods of exercise, such as racing or canine sports. Certain hormonal problems and even pets who are already suffering from a fever are also at increased risk.

Signs of Overheating in Dogs

Panting is one of the earliest and most common signs of an overheated dog, so pay attention if your dog is panting excessively, breathing unusually fast, and breathing is noisy. If your dog is just panting and you aren’t sure if they are in danger of overheating, you can take their temperature.

Heat stroke usually occurs at outdoor temperatures of 104° F and over (unless your pet is in an unventilated place, overweight, extra furry, or suffers from a medical condition that predisposes them to heatstroke). Remember, rectal temperatures are the most accurate way to take your dog’s temperature, however, if they have stool in their rectum, it will be artificially lowered.

You can check their gums to gather more information. Overheating is often associated with sticky gums that aren’t quite as moist as normal. While checking their gums, note the color; they may either be bright red or even purplish-blue.

Soon after, your dog may appear dull or disoriented. They may even collapse or convulse. Vomitingdiarrhea, and internal bleeding (manifesting as red/purple spots on the gums, skin, urine, or feces) may occur. Sudden death from cardiac arrhythmias is even a possibility.

An estimated 50% of dogs do not survive, with death generally happening within the first 24 hours of the incident. For dogs who survive 48 hours of hospitalization, the outcome is usually good.

What You Can Do if You Suspect Your Dog is Overheated

Recognizing the symptoms of heat stroke and responding quickly are essential for the best possible outcome. This is exactly what happened to Willow, a Labrador Retriever who suffered from heat stroke. Her pet parents, Charles and Erica reacted quickly to save her. If your dog is experiencing symptoms of heatstroke:

  • Move them out of direct sunlight and to a cool environment immediately, such as a shaded area or air-conditioned room or car

  • Wet your dog with cool (NOT ICE COLD) water, and head to the veterinarian ASAP

  • Wrap your dog in a wet towel on the way to the hospital, as lowering the temperature (slowly, not rapidly) is of crucial and timely importance

  • If your dog shows interest in drinking water, allow them by all means. If your dog is unconscious, make sure no water can get up their nose or mouth 

  • Call your vet while on your way so they can have a team prepared to act quickly! Even if you are only three minutes away, much work can be done in advance to effectively prep for your overheated loved one

What will the vet do to treat an overheated dog?

When you get to the vet, be prepared for your dog to be whisked away. It may be a few moments before a staff member can speak with you. The staff's ability to work quickly and effectively is important for your dog's survival.

The goals of heat stroke therapy are to safely lower the body temperature, treat shock or other negative consequences if they have occurred, and correct the contributing factors. While at the vet, cool IV fluids will likely be administered, and blood work will be run. If your pet is suffering more serious side effects, a breathing tube may need to be placed and artificial ventilation begun. Correcting electrolyte imbalances and controlling seizures are also of top importance. Depending on the severity of the heat stroke, hospitalization of multiple days may be required.

Preventing Overheating in Dogs

Proper care must be taken to avoid situations where your pet is at risk for hyperthermia. The best defense against heat stroke is to monitor your dog and their activities as most, if not all, cases are entirely preventable.

  • Never leave your dog unattended in a car, not even cracking windows can provide adequate ventilation or cooling. On a sunny day when ambient temperatures are 85° F (30° C), it takes less than 10 minutes for the internal temperature of a parked vehicle to reach 102° F (30° C), and less than 30 minutes to reach 120° (49° C) even with all the windows partly open

  • Ensure that pets have access to fresh water and shade while they’re outside

  • Keep exercising to a minimum on warm days as this is a contributor to overheating

  • Please remember animals that survive heat stroke are more susceptible to repeat occurrences