panting beagle dog sitting inside car waiting for travel dog heat stroke dog heat exhaustion overheating in dogs

The Signs Of Overheating In Dogs And How To Prevent Dog Heat Stroke

Heat stroke in dogs is very serious and dangerous. It can occur in as little as 30 minutes and become fatal within 60 minutes. That's why it's important to know what dog heat stroke symptoms look like, as well as dog overheating symptoms that lead up to heat stroke, so you can act quickly. So here's all about heat stroke in dogs, from the signs of overheating in dogs and how to prevent dog heat stroke to causes, risk factors, treatment and more.

What Is Heat Stroke In Dogs And Dog Heat Related Illness

Heat stroke in dogs is the most severe stage of heat related illness (HRI) caused by overheating. HRI in dogs occurs when the core body temperature elevates above normal levels, also known as hyperthermia. The three stages of HRI are heat stress, heat exhaustion and heat stroke (and the latter two occur when a dog is unable to cool down, which is why they are more severe than the first).

For more information, read our article on what temperatures are too hot for dogs.

What Is A Dog's Normal Body Temperature?

Normal temperatures for dogs fall between 99.5°F and 102.5°F - depending on size, weight, age, breed and condition of the dog. Body temperatures slightly above normal are considered fevers. In general, dogs start overheating when their temperature rises above 103°F and heat stroke occurs above 104° to 106°F.  Action is required at 104°F, and anything over 105°F is considered an emergency. When a dog's body reaches 107°F to 109°F,  brain damage, multiple organ failure and death can occur. 

Stages Of Heat Related Illness

Here are descriptions of the three stages of HRI (heat stress, heat exhaustion and heat stroke) and signs of each of them.

Heat Stress In Dogs (Stage 1)

Heat stress occurs when a dog gets too hot for a short period of time, but is typically able to cool off efficiently and avoid any serious consequences (other than mild dehydration or lethargy).

Signs Of Overheating In Dogs And Heat Stress Symptoms

  • Excessive panting (tongue may be protruding far out with a flattened end, cheeks may be pulled back to show all teeth even molars)
  • Increased thirst
  • Thick, sticky or pasty saliva in mouth
  • Excessive drooling or thick, sticky or pasty drool
  • Skin is overly warm to the touch
  • Less animated behavior, visibly tired or moving at slower paces
  • Bright or brick red tongue, gums and other mucous membranes
  • Changes in the dog’s attitude and focus (e.g. not responding to known commands, acting apprehensive, etc.)
  • Heat cramps or muscle spasms

Heat Exhaustion In Dogs (Stage 2)

Dog's in heat stress that continue to be exposed to warm temperatures will likely progress to heat exhaustion. Heat exhaustion occurs when a dog's temperature rises above a healthy range and they are unable to cool themselves down or thermoregulate. It can range from mild and treatable at home to more severe and requiring vet treatment.

Signs Of Heat Exhaustion In Dogs And Dog Heat Exhaustion Symptoms

Any of the signs from Stage 1 plus:

  • Excessive, uncontrollable panting and heavy, rapid breathing
  • Even more thirst
  • Elevated heart rate
  • Weakness, stumbling and difficult maintaining balance
  • Dry or sticky mouth, gums, nose and other mucous membranes (a hot and dry nose could mean your dog has a fever) 
  • Sunken dry eyes
  • Mentally aware but too tired to react
  • Vomiting or diarrhea (both with or without blood)
  • Lack of skin elasticity
  • Muscle tremors, such as shivering or shaking

    Heat Stroke In Dogs (Stage 3)

    Heat stroke is the most severe stage of HRI and occurs when a dog's body temperature rises above 104° to 106°F. It can affect several parts and systems of the body, but most often the heart (e.g. elevated heart rate), central nervous system (e.g. disorientation and seizures), gastrointestinal tract (e.g. vomiting and diarrhea, often bloody), kidneys, liver and coagulation (increased risk of bleeding). In addition, heatstroke can damage heat shock proteins, which are designed to protect from heat and stress, This can overpower the body’s defense mechanisms against heat and further limiting the ability to cool down.

    Signs Of Heat Stroke In Dogs And Dog Heat Stroke Symptoms

    Any of the signs from Stages 1 and 2, plus:

    • Incessant or noisy panting, hyperventilation and severe breathing distress
    • Pale, white, gray, blue, purple or otherwise abnormally colored gums, as well as bruising of gums
    • Very rapid heart rate or irregular pulse (to take your dog’s pulse, place your hand on their chest near the front elbow joint. Normal pulse rate depends on size - bigger dogs tend to have slower pulses, small dogs and puppies have very quick ones)
    • Dilated pupils
    • Drop in blood pressure
    • Disorientation, lethargy, significant slowness or unwillingness to move
    • Lack of coordination, wobbly or unsteady movements
    • Severe dehydration, dark urine or lack of urine
    • Uncontrollable urination or defecation
    • Weakness of their backside and hind area
    • Unresponsive or confused
    • Seizures
    • Shock
    • Collapse
    • Coma

      How Dogs Cool Down And Why Heat Can Be So Dangerous To Dogs

      Dogs have only a few ways to cool off and they're not always the most effective, especially once the body temperature is far too high. This is why they are more sensitive to heat and susceptible to HRI or overheating. Temperature regulation, or thermoregulation, is controlled by the hypothalamus in a dog's brain. When body temperature rises, the brain prompts the following to cool a dog down:

      • Panting - Through panting, dogs are able to evaporate moisture from their tongues, nasal passages and lung lining. This helps cool them down as air passes over the moist tissues.
      • Vasodilation - Expanding blood vessels brings overheated blood closer to the surface, which helps them cool down. 
      • Sweating - Dogs sweat small amounts from the paw pads and nose (but it's not usually enough to release body heat and make much a difference).

      Causes Of Heat Stroke In Dogs And Risk Factors For Dog Heat Stroke

      Any dog can get HRI and heat stroke in hot temperatures without the ability to cool down. But some causes of overheating are more common:

      • Exercise (even walking for seemingly short amounts of time)
      • Leaving dogs in cars, even on seemingly cooler days
      • Other hot, confined spaces with inadequate ventilation or cooling
      • Being left outside, like in the backyard, without access to shade or water
      • Limited access to drinking water
      • Living in areas of high humidity (e.g. HRI is more common in the Southern U.S., although climate change is expanding risk areas)
      • Sudden increases in temperatures
      • Extended exposed to air dryers (like for cages or hair)
      • Infections that cause fevers
      • Dogs with seizures or sever muscle spasms  

      Pro Tip: Research has shown that the temperature inside a car can increase by an average of 40°F per hour. 

      In addition, some dogs are at higher risk of overheating and developing HRI. These include:

      • Brachycephalic breeds (those with flat faces and smushed noses like French Bulldogs, Pugs, English Bulldogs etc. can overheat more quickly and in lower temperatures and humidity levels)
      • Breeds with fluffy or long hair and thick coats (like dogs bred for cold weather)
      • Dogs with heart disease
      • Overweight and obese dogs
      • Older dogs and senior dogs, as well as young puppies
      • Dogs with hypothyroidism and endocrine disorders
      • Dogs with laryngeal paralysis, tracheal collapse and respiratory issues
      • Dogs that wear muzzles (as muzzling restricts panting)
      • Overly excited dogs

      What To Do If Your Dog Has Heat Stroke Or Is Overheating And How To Cool Down A Dog Safely

      It's important to take immediate action if you think your dog is overheating, especially if they appear to be suffering from heat exhaustion or heat stroke. The goal is to carefully cool your dog's body temperature using a controlled and slow approach to cooling (rapid cooling can cause more problems).

      What To Do If Your Dog Is Overheating Or In Heat Stress

      • Take a break from outdoor activity.
      • Move to a cool, shaded area that's well ventilated. It's best to go inside where it's air conditioned or you can use a fan. If outside and unable to go inside, find in a shady area to sit in, preferably with a cool breeze.
      • Offer your dog lots of fresh water, but don't force them to drink. Also, prevent them from drinking too much at once as that can lead to vomiting.
      • Apply cool or room temperature (not cold) water to your dog's body, particularly the paw pads, underbelly, ears, armpits and groin. Room temperature is best for small dogs and puppies.
      • Rinse out the mouth to remove any pasty saliva from gums and tongue.
      • You can try dabbing rubbing alcohol-soaked pads to the armpits, groin area and outside of the ears (the alcohol supposedly can help quickly cool the surface blood).
      • Lay your dog down on a cool surface, like tile or in the bathroom, bathtub and shower.
      • Monitor your dog's temperature with a thermometer (preferably not glass) every few minutes.
      • Consult your vet for additional advice and suggestions.

      What To Do For Heat Exhaustion In Dogs

      • Go to a vet immediately and work to cool your dog on the way by taking a slow approach to cooling.
      • Place a cool (not cold), wet towel under your dog.
      • Apply cool or room temperature (not cold) water to your dog's body, particularly the paw pads, underbelly, ears, armpits and groin. Room temperature is best for small dogs and puppies.
      • You can try dabbing rubbing alcohol-soaked pads to the armpits, groin area and outside of the ears.
      • Make sure there's enough space for them to lay on their side (stretching out is important to maximize heat dissipation).
      • Use fans across your dog's entire body to help facilitate evaporative heat loss.

      What To Do If A Dog Has Heat Stroke 

      • Take your dog to the nearest vet immediately and work to cool your dog down through a slow approach to cooling.
      • Follow the afore-mentioned actions from heat exhaustion while transporting to the vet.
      • Don't take a "wait and see" approach

      Important Notes:

      DO NOT put extremely cold water or ice on your dog. The extreme cold will cause surface blood vessels to shrink and increase the risk of dehydration, drop in blood pressure, shock, overheating, heatstroke or further damage to organs.

      If using towels or rags, make sure to regularly re-wet or replace them as they warm up. Also, avoid covering the body with wet towels as that can trap heat.

      As your dog cools down, provide small amounts of cool or room temperature water. Continue to avoid giving them very cold water or ice and don't force them to drink.

      Once your dog's temperature is under 104°F or reaches 103°F, your dog's body should be able to cool itself down from there. It's recommended to stop cooling down your dog to avoid overcooling and hypothermia. It's a good idea to keep checking their temperature to ensure it doesn't drop too low and your dog doesn't get too cold.

      Even if your dog seems better, don't leave them unattended.

      Take your dog to the vet once their temperature is around 103°F, you're unable to cool them down or they lose consciousness or become severely ill (vomiting, seizures, etc.). Even if your dog seems better, it's a good idea to visit a vet as complications may not happen immediately and internal damage isn't always noticeable or visible - like shock, dehydration, kidney failure and more. A thorough examination, bloodwork and other testing can help assess damage and ensure the proper next steps are taken. Once your dog is in vet care, they may provide fluids, medication, oxygen, sedation and other support.

      Treating Heat Related Illness In Dogs And Dog Heatstroke Treatment 

      Treatment depends on the diagnosis and severity of HRI, but most dogs will need to be hospitalized. There, vets will monitor the dog's temperature, heart rate, blood pressure, respiratory rate and effort, mental status and more. Many will need to be treated for dehydration through IV fluids and sometimes medication to reduce or prevent vomiting and diarrhea. Antibiotics may also be given to prevent infection. Some may receive medication to help with brain swelling and seizures. Other treatments include oxygen therapy, plasma transfusions, anti-arrhythmic medications and electrocardiogram testing.

      Pro Tip: Vets will likely do bloodwork within one to two weeks after the HRI to make sure their organs are working properly and there's no delayed onset of damage.

      Dog Heat Stroke Survival Rate And Prognosis

      Prognosis also depends on the severity of HRI, including how high the body temperature rose, how long it was elevated for, if organ damage occurred and response of care. Other factors include the physical condition prior to HRI, age, breed (e.g. brachycephalic) and cause of heat stroke (for example, being left in cars usually results in the most severe cases).

      Dogs that survive the first 24 hours can make a full recovery. For dogs whose temperature was not extremely high, most will recover with quick action. But for dogs with multiple organ failure, the prognosis is poor. Some estimate that the general survival rate is around 50%. However, cooling your dog before arriving at the vet (using a controlled and slow approach) has been shown to increase chances of survival from 50% to 80% and prevent more damage. It's important to note that even dogs who survive may have permanent organ damage or neurological issues that require lifelong treatment, as well as shortened lifespans. They are also at greater risk for additional HRI because of damage to their thermoregulatory center.

      How To Prevent Heat Stroke In Dogs 

      Fortunately, there are ways to prevent HRI and heat stroke in dogs. Here are some of the best ways to do so:

      • Limit time outside and avoid activity during the hottest hours of the day.
      • Opt for exercise, play, training, etc. during cooler hours.
      • Always have fresh, cool water accessible or on hand (including on walks).
      • Make sure to have access to shade as much as possible.
      • Take frequent breaks and rest periods.
      • Avoid long walks, hills, inclines and hikes which require more exertion.
      • Don't leave your dog in the car.
      • Keep your dog inside on hot days, especially if they're at risk of HRI. Heat advisories are not just for humans!
      • Keep your house cool, even when you're not home, by leaving on air conditioning or fans for your dog.
      • Hire a pet sitter, take your dog to doggie daycare or use dog boarding for extended absences.
      • Know the risk factors and be aware if your dog has one (e.g. older, younger, brachycephalic, obese, heart disease, respiratory issues, etc.).
      • Learn how to read your dog's body language and non-verbal cues that they're overheating.
      • Make sure to always check humidity levels and how it's impacting the heat index. Humidity can make it feel much hotter than the thermostat says it is.
      • Always err on the side of caution and don't hesitate to contact a vet, even if you're unsure your dog actually has HRI.

      For more, read our article on ways to keep your dog safe in warm weather. Plus, some summer essentials that will help keep your dog safe.

            Back to blog

            Leave a comment

            Please note, comments need to be approved before they are published.