Picture this: It is a hot, summer day, and you and your dog have just returned from a long hike through the woods. You are sweating, out of breath, and ready for a big, cold glass of water. Your dog, on the other hand, is panting heavily, but you can’t see a drop of sweat on him. Just because you can't see it doesn't mean it isn't happening.
Contrary to popular belief, dogs do sweat, but sweating is only a small part of the process dogs use to cool themselves down in the heat. In fact, compared to humans, dogs are not very efficient at all, which is why it is up to us to help our dogs stay comfortable during temperature extremes.
Where Do Dogs Sweat?
There is a reason you have never seen your dog sweat the way you do, and that is because dogs only produce sweat in certain parts of their bodies. Dogs have two types of sweat glands:
- Merocrine glands
- Apocrine glands
Merocrine sweat glands function similarly to human sweat glands. These glands are located in the paw pads of your dog and activate when your dog is hot to help cool him off, which is why you might notice damp paw prints on the ground on very hot days.
Apocrine sweat glands are different from merocrine. While veterinarians consider them to be sweat glands, their main purpose is to release pheromones, not cool your dog off, which is why your dog does not come home with sweaty armpits after a run. These glands are located all over your dog’s body and help her identify other dogs by scent, kind of like human body odor, only without the need for antiperspirant and deodorants.
What’s the Point of Panting?
Sweat plays a very small role in cooling down your dog. Dogs rely on panting to do most of their temperature regulation. When dogs pant, they evaporate moisture from their tongues and the lining of their lungs, cooling them as air passes over the moist tissue. They also rely on vasodilation to help them cool off, which is the expansion of blood vessels, especially in their ears and face. When the blood vessels expand, they bring the blood closer to the surface, which allows it to cool down and regulate the internal body temperature of the animal.
Does Fur Make Dogs Hot?
If you or I put on a fur coat during a sunny July day, we would probably cook. Your dog’s coat, on the other hand, actually acts as an insulator. Think of it as a layer of insulation, like a thermos has, that keeps the dog either cool or hot as he goes about his day.
This insulating layer can backfire during continuous hot weather, however, as it can make it harder for dogs to lower their body temperatures. Going back to our thermos analogy, if you stick an insulated thermos of ice water in a hot car, it will eventually heat up over a few hours. Putting it in a freezer will cool it, but the insulation will keep the water warm for a long time. If a dog gets too hot, this means that it can take longer to cool down than it would for a furless human. Dogs with thicker coats are better insulated than dogs with thinner coats, which is why short-haired, single-coated dogs are typically more heat tolerant but less cold tolerant.
Heat Stroke in Dogs
Unfortunately, panting, vasodilation, and limited sweating are not as efficient at cooling dogs down as sweating is for humans. This poses risks during hot weather, ranging from heat stress and heat exhaustion to heat stroke.
Heat stroke is a serious concern for all dogs, but especially brachycephalic breeds, such as Pugs, Boxers, Bulldogs, Boston Terriers, French Bulldogs, and Shih Tzu. These breeds don’t sweat like we do, and they are also not able to cool themselves as effectively as other breeds, thanks to their unique anatomy.
Heat stroke occurs when dogs overheat, and if left untreated for too long it can be fatal. Every dog owner should be aware of the signs of heat stress and heat stroke, and dogs should always have access to shade and fresh water during the summer months.
Some symptoms of heat stress and heat stroke:
- Heavy panting
- Body temperature over 41 Celsius
- Excessive drooling
- Red gums
- Rapid or irregular heart rate
- Muscle tremors
- Lack of coordination (ataxia)
If you suspect your dog might be suffering from heat stroke or heat stress, call your veterinarian immediately, and get your dog to the hospital.
Keeping Your Dog Cool (and Warm)
We might not be able to make our dogs sweat, but we can help them regulate their body temperatures by keeping control of their environments. During the summer, make sure that any outdoor dogs have access to shade and plenty of clean, fresh water, and make sure that the temperature of the house is cool enough for indoor dogs. Never leave your dog in an unattended car during the summer, even for just a few minutes, as temperatures can quickly climb to a dangerous level.
During the winter, make sure that cold-intolerant breeds, like the Greyhound, or dogs with conditions such as hypothyroidism that make them cold intolerant stay warm, either by providing them with outdoor coats or by limiting their exposure to cold temperatures.
Exercise is an important part of your dog’s health. By learning how dogs regulate their body temperature, you can help keep your dog cool, safe, and healthy year-round.