Can Dogs Sweat? How Canine Cooling Actually Works
Most dog owners have heard some version of "dogs don't sweat, they pant"—and then noticed damp paw prints on the kitchen floor after a walk and wondered which one is true. Both are, in a sense, but the common version of this fact misses the part that actually matters for keeping a dog safe in the heat: dogs do have sweat glands, sweating contributes very little to cooling them down, and understanding why changes how you read the early warning signs of overheating.
The Sweat Myth, Corrected
Dogs have two types of sweat glands. Apocrine glands are distributed across most of the body but are tied to scent and skin health rather than temperature control, and they don't produce the evaporative cooling effect most people mean by "sweating." Merocrine glands, which function more like human sweat glands, exist only in a limited area: the paw pads, and some sources note, around the nose. When a dog gets hot, these glands can release a small amount of moisture, which is why you sometimes see faint wet paw prints on tile or pavement in warm weather.
The problem is scale. Paw pads make up a tiny fraction of a dog's total surface area, and the fur-covered rest of the body has no equivalent evaporative surface. So while the "dogs can't sweat at all" version of the myth is technically wrong, the practical takeaway is the same: paw-pad sweating is a minor, supplementary mechanism, not the dog's primary defense against heat.
Where the Real Cooling Happens
Dogs shed heat mainly through two connected pathways, and picturing them as a single heat-flow loop makes the rest of this easier to follow.
Panting drives evaporative cooling in the airway. As a dog pants, air moves rapidly across the moist surfaces of the tongue, mouth, and upper respiratory tract. Water evaporates from those surfaces, and evaporation pulls heat away with it, the same principle that makes sweat cooling work in humans, just relocated to the respiratory tract instead of the skin. This is why panting increases sharply, and audibly, well before a dog looks distressed.
Blood vessel dilation moves heat to the surface. Underneath a dog's fur, especially in areas with less hair, blood vessels near the skin widen to bring warm blood closer to the surface, where some heat can radiate away. Owners who feel a hot dog's belly, ears, or groin during exercise are noticing this mechanism in action, and it's also why those same areas are the ones veterinarians recommend targeting when cooling an overheated dog.
Both systems work by a normal margin under ordinary conditions. Trouble starts when the air is too hot, too humid, or too still for panting to keep pace, because evaporation slows as humidity rises. At that point, panting harder no longer buys much additional cooling, and body temperature can climb even though the dog is doing everything its body knows how to do.
Why Some Dogs Run Out of Cooling Capacity Faster
The heat-flow system above assumes a dog can move air efficiently and isn't fighting extra internal heat load. Several factors break that assumption.
Brachycephalic, or flat-faced, breeds, including Bulldogs, French Bulldogs, Pugs, and similarly built dogs, have restricted airways that make it physically harder to move the volume of air panting depends on. A large UK study using veterinary clinical records found flat-faced dogs had roughly double the odds of heat-related illness compared to normal-muzzled dogs, and identified specific breeds, Chow Chow, Bulldog, and French Bulldog among them, at several times the risk of a Labrador Retriever.
Being overweight for one's breed and size was independently associated with higher heat-related illness risk in the same analysis, and separate veterinary guidance notes that obesity impairs temperature regulation partly because excess tissue adds insulation while also making panting less effective in brachycephalic dogs specifically.
Larger body size carries its own risk. The same study found dogs over 50 kg had more than three times the odds of heat-related illness compared to dogs under 10 kg, independent of breed.
Age over two years also showed up as a significant risk factor in that dataset, alongside the breed and weight effects.
None of this means other dogs are immune, only that these factors lower the safety margin before heat becomes dangerous, and shorten how much time an owner has to notice a problem and act.
Reading the Signs: Hot and Uncomfortable vs. an Emergency
Because sweating isn't a useful visual cue in dogs, panting pattern and behavior are what actually signal trouble, and the signs form a rough progression rather than a single moment.
Early discomfort looks like heavier panting than the activity level would explain, seeking shade or a cool floor on its own, slowing down or wanting to stop a walk, and general restlessness. These signs are worth acting on immediately by moving the dog to shade or air conditioning and offering water, but they don't by themselves mean a veterinary emergency.
Signs that warrant urgent action include panting that doesn't slow down with rest, thick or excessive drooling, bright red gums or tongue, skin that feels hot to the touch, and a rapid heart rate or noticeable restlessness that doesn't settle once the dog is out of the heat. At this stage, cooling should start right away, and a call to a veterinarian or emergency clinic is reasonable even before symptoms escalate further.
True heatstroke is a medical emergency. Cornell University's veterinary college defines it as body temperature reaching roughly 105°F or higher, against a healthy dog's normal range of about 100.5 to 102.5°F, and lists the clinical picture as heavy panting, drooling, vomiting, diarrhea that is sometimes bloody, weakness, confusion, seizures, and collapse. Heatstroke can cause organ damage, commonly acute kidney injury, blood clotting problems, and shock, and Cornell notes that many affected dogs do not survive, with outcome depending heavily on how high the temperature climbed and how long it stayed elevated before treatment.
What to Do Before You Reach a Veterinarian
If a dog is showing urgent or emergency-level signs, the immediate priority is getting body temperature down while getting to veterinary care, not treating the situation at home instead of going in.
Move the dog out of the heat immediately, into shade or an air-conditioned space. Wet the dog with cool, not ice-cold, water, focusing on areas where blood vessels sit close to the skin: the belly, armpits, groin, and paws are the areas veterinary sources consistently point to. Point a fan at the wet dog or use a car's air conditioning while traveling, since moving air across damp skin speeds evaporative cooling. Offer small amounts of cool water if the dog is alert and drinking on its own, but don't force water into the mouth.
Avoid ice or ice water. Multiple veterinary sources specifically warn against it, because it can constrict surface blood vessels in a way that traps heat inside the body instead of releasing it, and can push a dog into shock or hypothermia during the cooldown. The goal is steady cooling on the way to care, not the fastest possible temperature drop.
Call ahead. Suspected heatstroke needs veterinary evaluation and monitoring even after a dog seems to perk up with cooling, because internal organ damage can lag behind visible improvement. This is a same-day-at-minimum, often immediate, veterinary decision rather than something to manage by observation alone.
Lowering the Odds Before It Becomes an Emergency
Most heat-related emergencies are avoidable with attention to timing and setting rather than any product or gadget. Avoiding strenuous exercise and walks during the hottest part of the day, never leaving a dog in a parked car, ensuring constant access to shade and water outdoors, and staying alert to a brachycephalic, overweight, senior, or large-breed dog's lower margin for error all reduce the chance of reaching the emergency stage in the first place.
Cooling mats, vests, and similar products that rely on evaporation or gel-based heat absorption can provide some added support for dogs at higher risk, but they work alongside the dog's own mechanisms rather than replacing shade, water, and reduced activity during genuinely hot conditions.
Owners managing a brachycephalic breed, a senior dog, or a dog carrying extra weight may find it useful to review breed- and condition-specific supportive products in Hero Veterinary's dog care collection as part of a broader heat-season routine, alongside, not instead of, guidance from their veterinarian about what their individual dog can safely tolerate.