On hot summer days, your canine companion feels the heat just as much as you do. While their coat helps them regulate their temperature more precisely than humans can, dogs have very few sweat glands.
There are a few on the pads of their paws and in their ear canals, but these are not enough to cool them down on a hot day. While our bodies produce sweat in order to cool our skin, dogs must resort to other means to stay cool.
Heat Tolerance by Breed
All dogs are vulnerable to overheating, though some breeds have a higher tolerance for heat than others.
Breeds originating in hot climates—such as Pharaoh Hounds and Basenjis—as well as racing breeds with long noses and big lungs—such as Whippets, Greyhounds, and Salukis—are more comfortable in the heat than other breeds.
Dogs with thin or short coats—such as Dalmatians, Chihuahuas, and most Beagles—are also better able to withstand the heat.
Some breeds, however, are more likely to suffer the effects of heat; these include giant breeds, breeds with thick or heavy coats, and brachycephalic, or short-nosed, breeds, such as Bulldogs, Boston Terriers, French Bulldogs and Pugs.
How Dogs Try to Keep Cool
Dogs use a number of strategies to cool off. The most direct solution is panting, which evaporates moisture from the mucous membranes in their mouths, cooling their heads and faces.
Inside their bodies, blood vessels in their skin and tongue will dilate, making it easier for internal heat from their blood to radiate out.
They will naturally shed their inner coat, making it easier for air to circulate beneath their outer coat and keeping their skin at a comfortable temperature. Their outer coat remains to provide protection from the sun and insulation against hot air.
Like most creatures, dogs will further attempt to cool down by seeking out shady spots, cool surfaces on which to lie down, including patches of dewy grass, and places where the air is moving.
Some dogs will dig out the warmer upper level of the ground to create a cool nest of fresh dirt. Many dogs will stand in a pool of water or puddle to cool the exposed skin on their paw pads, or they will submerge their chest, which, because of their internal anatomy, often becomes the hottest part of their body.
Despite all of the instinctual and physiological strategies that dogs use to stay cool on a hot day, it is still possible for them to suffer from dehydration and heat stroke. This is especially possible if they are left outside, in a truck bed, or in a car on a hot day. Never neglect your dog on a hot summer day and learn to look for the signs of possible heat illness before it’s too late.
Symptoms of Dehydration and Heat Stroke in Dogs
According to the American Kennel Club, if your dog is suffering from heat stroke, there will be some clear signs. Early symptoms include:
- Excessive panting and hypersalivation, or drooling
- Lying down and refusing or being unable to stand, or otherwise being poorly responsive
- Overly dry nose
- Rapid heart rate (anything over 140 beats per minute for most adult dogs)
- High body temperature (anything over 105 degrees Fahrenheit for most adult dogs; you can often detect this high a temperature simply by touch)
- Mucous membranes in the mouth become mottled dark red or purple
Symptoms of advanced heat stroke that require immediate medical attention include:
- Bleeding from the mouth or blood in the stool
- Seizures and muscle tremors
- Poor balance and ataxia (staggering when moving)
The symptoms of dehydration in a dog are similar to those of heat stroke, but there are some subtle differences. If your dog is not drinking enough water, or if your dog is losing bodily moisture faster than it can be replaced (for example, through excessive panting due to heat stroke or overly hot conditions), you will notice any of the following:
- Loss of appetite
- Excessive panting
- Reduced energy-levels and general lethargy
- Increased looseness and sagging of skin and sunken eyes
- Vomiting and/or diarrhea
- Overly dry nose, eyes, and gums
- Thick saliva
All dogs are susceptible to heat illness, but the threshold for concern varies depending on some factors.
Obese and overweight dogs are much more likely to suffer the effects of excessive heat. Puppies, older dogs, and those with underlying medical conditions (particularly diabetes) are also at an elevated risk.
Effects of Dehydration and Heat Stroke in Dogs
If left untreated, the effects of dehydration and heat stroke in your dog can be profound and tragic.
Bodily trauma from too much heat can cause lasting physiological and psychological damage, including brain damage, sensory impairments, digestive ailments, permanent muscle loss, and blood conditions.
Physical burns on the dog’s paw pads from walking on hot pavement risk becoming infected or leading to permanent mobility problems.
The shock and damage caused by sustained heat stroke that lasts more than 30 minutes or dehydration that lasts more than 48 hours can lead to death.
Treating Dehydration and Heat Stroke in Dogs
If you observe any of the symptoms of heat stroke or dehydration in your dog and have reason to believe they may be suffering from one of these ailments, you must take immediate action.
While you want to avoid cooling your dog too rapidly, your primary goal is to lower the body temperature and introduce more moisture into the body.
If the dog is outside, move the animal indoors to a cool environment and contact your vet immediately.
Apply cool, wet towels to the dog’s body, and especially beneath its legs, on its belly, and around its groin. Place a fan so that it moves air across the dog. Lightly mist the dog’s body with a spray bottle.
Make sure you place plenty of cool, fresh, clean water near your dog, but do not be alarmed if it takes a while before the dog wants to drink.
Dogs who do not want to drink at all might be encouraged if you add chicken broth, carrot juice, or some small ice chips to the water bowl. If the animal is suffering profound dehydration, a vet may need to apply IV fluids to restore homeostasis to its body.
If you have access to a canine thermometer, check your dog’s temperature every five minutes. Once the temperature is below 103 degrees Fahrenheit, ease off the cooling regimen.
How to Help Your Dog Stay Cool in the Summer
The safest and most effective way to keep your dog from suffering from dehydration and heat stroke, of course, is to adopt preventative measures. Here are some things to do and not to do in order to keep your dog safe on a hot summer day.
- Put out additional water bowls around the house and refresh them daily or sooner if empty (at our house this needs to be done every couple of hours!)
- If outdoors, make sure there are plenty of shaded areas for them to retreat to and that a source of cool, clean water is available to them
- Place out damp towels for them to lie on
- Turn on the sprinkler or put out a shallow pool that they can step into
- Only take walks in the early morning or evening, when temperatures are lower
- To test the heat of a surface, such as pavement or sand, place the back of your hand against it; if you cannot hold your hand against it for at least three seconds without experiencing pain, it’s too hot for your dog’s paw pads
- Provide wet, canned food, replacing dry food portions if needed; consider freezing wet food for a cool treat
- An ice cube can make a fun, and cool, treat for your dog
- Keep your dog’s coat properly groomed and comb out any tangles; if your vet recommends trimming the coat, be sure to leave at least one inch of fur for sun protection and insulation
- Consider using a canine sunscreen if your dog’s coat is particularly light or thin, is bald or balding, is a Nordic breed, or is prone to autoimmune diseases, but never use a human sunscreen on a dog
- If your dog’s eyes are sensitive, your vet might recommend canine eye protection; never use human sunglasses on a dog, however
- If you take a walk or go hiking with your dog, make sure that you bring along plenty of water for your dog as well as yourself
Dogs have similar temperature tolerances as humans, so if the weather outside is too hot for you, never leave your dog outside unattended in it; most vets recommend a temperature of no more than fifteen minutes outside if the temperature is 85 degrees Fahrenheit or above
- Never leave a dog in a vehicle, no matter the temperature outdoors and no matter if the windows are open or not; even if the car is left running with the air conditioning on, your dog will be at risk of rapid heat stroke death if the vehicle stalls and the air conditioning goes off
- Do not shave your dog’s coat
- Do not place a dog’s water bowl in the sun or anywhere that it might heat up
- Do not allow your dog access to the area around your car or other vehicles; hot weather can often cause coolant leaks in vehicles and if a dog ingests even a small amount of this sweet-tasting liquid, it can make the animal extremely ill and even lead to death
Stay safe and have fun with your pup this summer!