# Dog Not Eating in Hot Weather: Causes and What to Do Dogs not eating in hot weather is common and often mild. Heat can dull a dog's appetite the same way it can dull yours, and many dogs eat less on hot days and return to normal when it cools off. The problem is telling a harmless summer dip apart from heat stress or an illness that needs a veterinarian. This article is educational and is not a substitute for veterinary diagnosis or treatment. ## Quick Answer - A mild appetite dip on a hot day is usually normal if your dog still drinks, plays, and acts like itself. - Heat stress is different. Watch for rapid panting, a bright red tongue, red or pale gums, thick sticky saliva, weakness, vomiting, or diarrhea [1]. - Never leave a dog in a hot car or outside without shade in hot, humid weather. These are the most common situations that cause heatstroke [2]. - Offer cool water often, feed during the coolest parts of the day, and keep walks short when it is hot. - If your dog stops eating for more than a day, or shows any heat stress sign, call your veterinarian. ## What Appetite Loss in Hot Weather Looks Like A dog with a heat-related appetite dip usually still wants water. Your dog may sniff the bowl, eat a few bites, and walk away. Some dogs skip breakfast on a hot morning and eat a full dinner once the sun goes down. Energy level stays close to normal. Gums stay pink and moist. Breathing is normal for the temperature. Heat stress looks different. The dog may refuse all food and seem dull or weak. Panting becomes rapid and heavy. The tongue can look bright red, and the gums may be red or pale. Saliva turns thick and sticky [1]. Some dogs vomit or have diarrhea, and vomit may contain blood [1]. Dogs cool themselves mainly by panting because they only have sweat glands on their paws [2]. That makes hot, humid weather harder on them than on people. Short-muzzled breeds such as Pugs, Bulldogs, Boston Terriers, and Boxers cannot pant as efficiently, so they overheat more easily [2]. Dogs with underlying medical conditions are also at higher risk, even during normal activity [1]. ## Main Causes of Dogs Not Eating in Hot Weather Several things can explain why a dog's appetite drops when it is hot. Some are harmless. Some are serious. ### Heat and Appetite Heat itself can reduce how much a dog wants to eat. A study of dogs walking outdoors in a hot, sunny region found that when radiant heat load rose above a certain threshold, the dogs' breathing rate climbed sharply, from about 47 breaths per minute to 374 breaths per minute, and their water intake rose by about 215 mL compared with cooler walks [3]. A dog working that hard to stay cool may have little interest in food. ### Other Causes to Consider Appetite loss in summer is not always about heat. Dental pain, stomach upset, infections, and other illnesses can show up at any time of year. If your dog also has vomiting, diarrhea, or weight loss, the heat may not be the real problem. Our guide to [Dog Not Eating: When to Worry and What to Do](/knowledge/veterinary-medicine/digestive-and-urinary-care/dog-not-eating-when-to-worry) walks through the general causes. | Cause | Typical clues | How urgent | |---|---|---| | Mild heat-related appetite dip | Eats less on hot days, still drinks, normal energy, normal gums | Monitor at home | | Heat stress or heatstroke | Rapid panting, bright red tongue, red or pale gums, thick sticky saliva, weakness, dizziness, vomiting, diarrhea [1] | Emergency now | | Dehydration | Dry gums, skin that stays tented when gently pinched, sunken eyes, less urine | Same day | | Dental or mouth pain | Drooling, dropping food, chewing on one side, bad breath | Routine visit, sooner if not eating | | Stomach upset or infection | Vomiting, diarrhea, fever, hiding, low energy | Same day | | Stress from heat and routine changes | Panting at rest, pacing, restless nights, picky eating | Monitor, call if it lasts | ## Red Flags That Make It an Emergency Some signs mean you should stop reading and call a veterinarian or an emergency clinic right away. Heatstroke is a life-threatening emergency caused by a marked rise in body temperature after prolonged heat or humidity exposure, or after hard exercise in the heat [2]. Signs include rapid panting, a bright red tongue, red or pale gums, thick and sticky saliva, depression or lethargy, weakness, dizziness, vomiting, diarrhea, shock, coma, and death [1]. Heatstroke can also lead to kidney failure, spontaneous bleeding, an irregular heartbeat, and seizures, and these problems can appear hours or even days later [1]. Call for emergency help now if your dog: - Collapses, staggers, or seems confused - Has gums that are bright red, pale, or gray - Breathes with obvious effort or makes a lot of noise breathing - Vomits repeatedly or has bloody vomit or diarrhea - Feels hot to the touch and will not settle - Cannot stand or seems to be losing consciousness Do not wait to see if your dog improves on its own. Heatstroke gets worse quickly. ## What You Can Do at Home Safely If your dog is alert, drinking, and only mildly off its food, these steps can help while you watch for changes. ### Cooling and Hydration Move your dog to a cool, shaded, or air-conditioned space. Offer small amounts of cool water often. Do not force water into your dog's mouth, since that can cause choking. You can add a little water or low-sodium broth to food to boost fluid intake. A cool, damp towel on the belly and paws can help a dog that is panting heavily. Never use ice-cold water or ice packs for a dog that may be overheating, because that can cool the body too fast. If you suspect heatstroke, cool gently with room-temperature water and get to a vet. ### Encouraging Eating Try feeding during the coolest hours, early morning or late evening. Warm food smells stronger, but in hot weather a slightly cool or room-temperature meal may be more appealing. You can offer small, frequent meals instead of one large bowl. A spoonful of plain canned pumpkin or a splash of broth over regular food often tempts a picky dog. Avoid switching to a completely new diet all at once, since sudden changes can cause diarrhea. If your dog is drinking but not eating, our article on [Dog Not Eating but Drinking Water: What to Do](/knowledge/veterinary-medicine/vet-visit-decisions/dog-not-eating-but-drinking-water) covers that pattern in more detail. If diarrhea is part of the picture, see [Dog Diarrhea and Not Eating: Causes and When to Act](/knowledge/veterinary-medicine/digestive-and-urinary-care/dog-diarrhea-not-eating). ### What Not to Do Do not give human medications for nausea, pain, or appetite without veterinary guidance. Many common human drugs are toxic to dogs, and the correct dose depends on your dog's weight and health. Your veterinarian calculates any medication dose for your pet. Do not leave your dog alone in a car, even for a few minutes, and do not exercise your dog in the heat of the day [1]. ## What Your Veterinarian Will Check and Test Your veterinarian will start with a full physical exam. They will check your dog's temperature, heart rate, breathing, gum color, and hydration. They will look inside the mouth for dental disease or foreign objects. They will feel the abdomen for pain, swelling, or masses. Depending on what they find, your vet may recommend blood work to check organ function and electrolyte levels, a urine test, or imaging such as X-rays or ultrasound. If heatstroke is suspected, your vet will focus on cooling your dog and supporting circulation, then monitor for the delayed complications that can follow, including kidney problems, bleeding, and heart rhythm changes [1]. Tell your vet exactly what you saw at home. Note how long your dog has not eaten, how much water it is drinking, whether there was vomiting or diarrhea, and how much time it spent in the heat. That history helps your vet decide how urgent the situation is. ## Preventing Appetite Loss in Hot Weather Prevention is mostly about limiting heat exposure and keeping water available. Walk your dog in the early morning or late evening. A study of dogs walking in a hot, sunny region found that walking when radiant heat load was high caused large jumps in coat temperature, skin temperature, breathing rate, and water intake compared with cooler walks [3]. Keep walks short when it is hot, and choose shade and grass over hot pavement. Never leave your dog in a parked car. Temperatures inside a car can rise quickly, even on mild days [1]. If your dog lives outside, provide shade and constant access to fresh water, and bring your dog indoors during the hottest hours [2]. Know your dog's risk level. Short-muzzled breeds and dogs with medical conditions are at higher risk even during normal activity [1]. All dogs can develop heatstroke, so every dog needs heat precautions [2]. Watch body condition and weight over the summer. If your dog is eating less for weeks, weigh your dog or ask your vet to weigh it. Gradual weight loss is a reason to schedule a visit even if your dog seems otherwise fine. For a broader look at appetite changes, see [Why Is My Dog Not Eating?](/knowledge/veterinary-medicine/symptom-guides/why-is-my-dog-not-eating) and [My Dog Won't Eat: When to Worry](/knowledge/veterinary-medicine/vet-visit-decisions/dog-wont-eat-when-to-worry). ## Limitations and When to Contact a Veterinarian This article cannot tell you what is wrong with your individual dog. Only a veterinarian who examines your dog can do that. Use the timing below as a guide. **Emergency now:** Collapse, trouble breathing, bright red or pale gums, repeated vomiting, bloody diarrhea, seizures, or any dog that feels extremely hot and will not respond normally. Heatstroke is a life-threatening emergency [2][1]. **Same day:** Your dog has refused all food for 24 hours, is drinking much less, has vomiting or diarrhea, seems painful, or is dull and hiding. **Routine visit:** Your dog eats less on hot days but still drinks, plays, and holds weight. Mention it at your next checkup, or call sooner if it lasts more than a couple of days. **Call your veterinarian or a pet poison hotline** if you think your dog ate something toxic or you gave a medication by mistake. Your veterinarian can calculate the right dose of any drug based on your dog's weight and health. ## Frequently Asked Questions ### Is it normal for a dog to eat less in hot weather? Yes, a mild appetite dip on hot days can be normal. Many dogs eat less when temperatures rise and return to normal eating when it cools down. The key is whether your dog still drinks, acts like itself, and holds steady weight. ### How long can a dog go without eating in the heat? A healthy adult dog can often skip a meal or two without harm, but a full day without food is a reason to call your veterinarian. Puppies, small dogs, and dogs with medical conditions should be seen sooner. If your dog also vomits, has diarrhea, or seems weak, treat it as urgent. ### Can heat stress cause a dog to stop eating? Yes. A dog working hard to stay cool may lose interest in food. Heat stress also causes panting, weakness, and stomach upset, which can further reduce appetite [1]. If your dog shows those signs, cooling and veterinary care matter more than getting a meal in. ### Should I force my dog to eat when it is hot? No. Never force food into your dog's mouth, since that can cause choking. Instead, offer small meals at cooler times, add water or broth to food, and keep fresh water available. If your dog refuses food for more than a day, call your veterinarian. ### What temperature is too hot to walk my dog? There is no single number that fits every dog, because breed, age, health, and humidity all matter. Research on dogs walking outdoors found that high radiant heat load caused large increases in breathing rate and water intake, so avoid walks when the sun is strong and surfaces are hot [3]. A good rule is to walk early or late, keep it short, and watch your dog for heavy panting or slowing down. ## Related Articles - [Dog Not Eating: When to Worry and What to Do](/knowledge/veterinary-medicine/digestive-and-urinary-care/dog-not-eating-when-to-worry) - [Why Is My Dog Not Eating?](/knowledge/veterinary-medicine/symptom-guides/why-is-my-dog-not-eating) - [My Dog Won't Eat: When to Worry](/knowledge/veterinary-medicine/vet-visit-decisions/dog-wont-eat-when-to-worry) - [Dog Diarrhea and Not Eating: Causes and When to Act](/knowledge/veterinary-medicine/digestive-and-urinary-care/dog-diarrhea-not-eating) - [Dog Not Eating but Drinking Water: What to Do](/knowledge/veterinary-medicine/vet-visit-decisions/dog-not-eating-but-drinking-water) - [Dog Not Pooping but Eating Normally: Causes and Solutions](/knowledge/veterinary-medicine/digestive-and-urinary-care/dog-not-pooping-eating-normally) - [Dog Loss of Appetite: Causes and When to Worry](/knowledge/veterinary-medicine/digestive-and-urinary-care/dog-loss-of-appetite-causes) - [Senior Dog Not Eating: Causes, Weight Loss and What to Do](/knowledge/veterinary-medicine/digestive-and-urinary-care/senior-dog-not-eating) - [Pregnant Dog Not Eating: Causes and What to Do](/knowledge/veterinary-medicine/digestive-and-urinary-care/pregnant-dog-not-eating) ## References 1. [Heat Stroke in Dogs](https://www.petpoisonhelpline.com/uncategorized/hot-weather-dog-know-signs-heat-stroke/). Pet Poison Helpline. 2. [Summer heat safety tips for dogs](https://www.vet.cornell.edu/departments-centers-and-institutes/riney-canine-health-center/canine-health-topics/summer-heat-safety-tips-dogs). Cornell University College of Veterinary Medicine. 3. [Cool and safe walks: heat stress threshold for domestic dogs living in hot and sunny regions](https://pubmed.ncbi.nlm.nih.gov/42274809/). International journal of biometeorology, 2026. ## Further Reading - [Merck Veterinary Manual: Dog Owners](https://www.merckvetmanual.com/dog-owners) - [Cornell Richard P. Riney Canine Health Center: Canine Health Information](https://www.vet.cornell.edu/departments-centers-and-institutes/riney-canine-health-center/canine-health-information) - [American Veterinary Medical Association: Pet Care](https://www.avma.org/resources-tools/pet-owners/petcare)