Every summer in Montreal, veterinary clinics see a predictable and preventable wave of heat-related emergencies. Dogs brought in after midday walks on scorching pavement. Cats showing signs of dehydration. Pets that seemed fine in the morning and were in crisis by afternoon. Summer pet safety in Montreal is not a niche concern for anxious owners. It is a practical, urgent issue that every dog and cat owner in the city needs to understand before the heat arrives.
Montreal summers are genuinely extreme by Canadian standards, and the risks for pets are different from the risks for people. This guide covers what those risks are, which animals face them most, how to recognize when something is wrong, and what to do about it. At every stage, your first call when in doubt should be your veterinarian. At Liesse Animal Clinic in Dorval, the team is dedicated to treating pets with dignity, kindness and love, with preventive care as the foundation of everything they do.
Most Montrealers already know that summer here can be brutal. What they may not fully appreciate is how much more dangerous that heat is for animals than for humans.
During Montreal heat waves, daytime highs routinely climb above 30C, and with the humidex, the felt temperature can exceed 40C. Environment Canada has described the combination of sustained highs and overnight lows that stay above 20C as a "dangerous combination," with heat fatigue accumulating in the body over consecutive days.
Recent summers have made the pattern undeniable. On June 19, 2024, Montreal broke its previous June temperature record, with the mercury reaching 33.7C. In June 2025, temperatures hit 35.1C, breaking a record that had stood since 1964. The summer 2025 forecast indicated that intense humidity and heat would continue throughout the season. The first heat wave of summer 2025 saw humidex values reaching 46C in Montreal, driven by a weather phenomenon called a Bermuda High.
For pets, the danger is not limited to declared heat waves. A clear July afternoon with temperatures in the high twenties, combined with humidity and direct sun, can be sufficient to cause heat exhaustion in a dog walked during peak hours or left in a parked car. The Quebec government explicitly warns that pets should never be left alone in a car, even for a few minutes and even with windows open. On a warm day, car interior temperatures can become fatal within minutes.
The humidity factor is what makes Montreal particularly hard on animals. Humans cool down primarily through sweating. Dogs cool down almost entirely through panting, and cats through a combination of panting and grooming. Neither mechanism is anywhere near as efficient as human perspiration, and both become significantly less effective when the air is already saturated with moisture.
Not all dogs and cats face the same level of risk during a Montreal summer. Understanding where your pet falls on the vulnerability scale is the starting point for making smart decisions.
Brachycephalic (flat-faced) breeds are the highest-risk category. Brachycephalic breeds like pugs, French bulldogs, Boston terriers, and Persian cats are especially at risk due to their restricted airways. These breeds cannot pant efficiently enough to release heat at the rate a healthy dog's body produces it in warm conditions. Some dogs with short snouts can become overheated from excitement or stress even on days that are not particularly hot.
Senior pets and puppies or kittens have less efficient thermoregulation than healthy adult animals and fatigue faster in the heat.
Overweight pets are at elevated risk. Extra body mass generates more heat, and fat insulates the body against the cooling that panting or grooming provides.
Thick-coated breeds including Huskies, Malamutes, Saint Bernards, and Persian cats are at higher risk. Their coats, which serve them well in winter, become a liability in July.
Pets with underlying health conditions, particularly cardiac or respiratory disease, are significantly more vulnerable. A heart condition that is manageable in a cool environment can become life-threatening in sustained heat.
Pets with short snouts, thicker coats, and obesity are more likely to get heatstroke because it is more difficult to regulate body temperature. If your dog or cat falls into any of these categories, summer care requires extra attention and, ideally, a conversation with your vet about heat management before the season starts.
Heatstroke in pets is a medical emergency. The difference between catching it early and catching it late can determine whether your animal survives. Every dog and cat owner in Montreal should know these signs before summer begins.
Panting that progresses to distressed or noisy breathing is one of the first signs of overheating. Restlessness or agitation, pacing, and seeking shade or water are also early indicators.
Rapid panting to the point of near hyperventilation means a dog is on the brink of heatstroke. Brachycephalic breeds will often snort, which is a clear sign to get them cooled down immediately.
In cats, signs of heatstroke are often more subtle than in dogs. Cats are less likely to pant than dogs, which makes recognition harder. If a cat is panting heavily on a hot day without exertion, it means they are already overheating or have a serious medical condition, and immediate veterinary attention is required.
Signs of more serious heatstroke include heavy panting, drooling, vomiting, diarrhea, weakness, and collapse. As a dog's temperature increases beyond 104F, central nervous system symptoms including disorientation and seizures can occur, along with multiple organ dysfunction.
The recommended immediate first aid response is to cool first and transport second. Take the pet to a cool, well-ventilated area or use a fan, and offer small sips of water without forcing them to drink. Pouring water cooler than the pet's body temperature over them, combined with air movement from a breeze, fan, or air conditioning, is an effective cooling approach.
Do not use ice. Do not submerge the animal in ice-cold water. Then get to your veterinarian immediately. Seek emergency veterinary care if the animal is unresponsive or has lost consciousness, if symptoms persist despite initial cooling efforts, or if breathing becomes laboured or shallow.
Liesse Animal Clinic offers emergency services for pets during operating hours. If you are in the West Island and concerned about your pet in summer heat, call ahead.
One of the most common and preventable causes of summer injury in dogs is hot pavement. The problem is not just the air temperature. It is the surface your dog is walking on.
If the outside temperature is a pleasant 25C, there is little wind, and humidity is low, asphalt and tarmac can reach a staggering 52C. When the air temperature is 25C, asphalt can reach up to 58C. At 30C, pavement can hit 64C. Dog paw pads, while tough, are not designed to absorb that kind of heat. Burns, blistering, and serious tissue damage can occur within minutes.
The simple test: touch the pavement with the back of your hand for seven seconds. If you cannot hold it there for the full seven seconds, it is too hot for your dog's paws.
The best times to walk your dog in summer are early morning, before 10 AM, and evening, after 6 PM. During the midday and early afternoon hours, Montreal's West Island sidewalks, parking lots, and roads retain heat from hours of sun exposure. Even after the air cools, asphalt continues radiating stored heat well into the evening.
Grass and shaded paths are significantly cooler than open pavement. Parks with tree cover, such as the green spaces along the waterfront in Pointe-Claire or shaded neighbourhood trails, are far safer during summer than exposed sidewalks. Darker surfaces like black asphalt absorb and hold more heat than lighter surfaces such as concrete, and pavement in full sun can reach dangerously high temperatures even in the late morning, long before peak heat of day.
For flat-faced breeds, short-legged dogs, and senior animals, walking time should be reduced significantly during summer regardless of the time of day.
If there is one thing that reduces heat risk more than any other single factor, it is consistent hydration. A well-hydrated pet tolerates heat far better than a dehydrated one. The challenge is that many pets, particularly cats, are poor drinkers under normal conditions. Summer demands a deliberate approach.
Fresh, cool water should be available at all times, including outdoors during walks. Carry a collapsible bowl and water on any outing longer than 20 minutes. On hot days, change the water bowl frequently so it stays cool rather than reaching ambient temperature. Dogs that eat dry kibble exclusively have a higher baseline dehydration risk. Adding water or a small amount of low-sodium broth to meals is an easy way to increase fluid intake.
Adding some canned food to a cat's meals during the warmer days of the year provides additional hydration in case they do not drink enough. Encouraging a cat to drink with tuna water or another enticer can also be effective, especially on hot days.
Many cats drink more readily from a moving water source. A pet fountain is a reliable long-term investment for any cat owner. Multiple water stations placed around the home, particularly in cool rooms, will also increase consumption.
Lethargy, sunken eyes, dry or tacky gums, and skin that does not spring back quickly when gently pinched are all signs of dehydration in both dogs and cats. If you observe these signs in summer heat, get to your vet. Dehydration and the early stages of heat exhaustion can look similar and reinforce each other quickly.
At Liesse Animal Clinic, preventive care through regular examinations and proper diets is a core part of their approach to animal health. A summer wellness visit is a good opportunity to discuss your specific pet's hydration needs and heat tolerance.
Heat safety often dominates the summer pet conversation, but Montreal's warm months bring a second wave of risk that deserves equal attention: parasites. Fleas, ticks, and mosquitoes are all more active during the summer season, and each poses a genuine health threat to dogs and cats in the West Island.
In Canada, the flea risk period is typically May through October, though some households experience flea problems throughout the year. Fleas do not just cause itching. They can trigger allergic dermatitis, transmit tapeworms, and cause anemia in small or young animals. Critically, fleas do not need a wooded environment. They are present in backyards, parks, and urban green spaces throughout the West Island.
Ticks are active above four degrees Celsius, and in warmer years, that activity can begin as early as April in the Montreal area. The parasites can carry a variety of diseases, including Lyme disease. Any dog or cat that spends time outdoors in grass, parks, or natural areas during summer should be checked regularly for ticks. Pay close attention to areas around the ears, neck, between the toes, and under the legs.
This is the parasite risk that catches the most Montreal pet owners off guard. Heartworm is transmitted through mosquito bites, and veterinarians recommend heartworm protection for all dogs during mosquito season, with monthly prevention medication given from June through November. Heartworm testing should also be done annually, as a blood test can detect adult heartworms before clinical signs become apparent.
Heartworms are parasites that live in the heart and surrounding blood vessels. Unrecognized and untreated heartworm infections can be fatal, and symptoms, including difficulty breathing, coughing, and weight loss, often do not appear until advanced stages of the disease.
The good news is that all of these parasite risks are highly preventable with the right products. At Liesse Animal Clinic, the team can recommend a parasite prevention plan suited to your pet's specific risk level and lifestyle. Do not wait until a problem appears. Parasites are a summer-long threat, and prevention started early is far more effective than treatment started late.
Montreal's summers are genuinely beautiful, and there is no reason your dog or cat cannot enjoy them safely with the right preparation. Walk early or late. Stay off hot pavement. Keep water available constantly. Know the signs of heatstroke, and act fast if you see them. Get parasite prevention in place before mosquito season starts.
Liesse Animal Clinic has been the first full-service veterinary clinic in West Island, serving pets in Dorval and beyond since 1950, with over 70 years of experience and a commitment to excellence that defines them today. If you have questions about your specific pet's summer risk, a wellness visit is the right place to start. The team at Liesse Animal Clinic has seen every summer situation the West Island has to offer, and they are ready to help you keep your animal healthy through all of it.
Ready to set your pet up for a safe summer? Book a wellness visit with the team at Liesse Animal Clinic. With over 70 years of experience serving West Island pets, they can assess your animal's specific heat tolerance, recommend the right parasite prevention, and make sure you are heading into the season prepared.
