Healthy Hydration Helps Dogs Beat Heat Stress


The dog days of summer don’t have to be unbearable. Practicing healthy hydration and understanding the signs of heat stress and how to deal with it can help reduce the dangers of overheating in your active and hardworking dogs.

Keep in mind that dehydration can occur rapidly. Dogs that exercise 30 to 60 minutes at 70 to 80 degrees can experience mild to moderate dehydration, depending on the activity and the intensity. Among the effects of dehydration is an impaired ability to maintain a normal body temperature.

The most common risk to a working dog is an excessive increase in body temperature, causing heat stress. The level of crisis ranges from simply making a dog uncomfortable to a life-threatening situation.

Differences Between Signs of Heat Stress & Heatstroke

Heat Stress

  • Shade-seeking behavior
  • Lethargy
  • Heavy panting, possibly with tongue curled up
  • Lack of coordination
  • Loss of focus and motivation for training
  • Squinting of the eyes


  • Distressed and anxious behavior
  • Profuse, thick drooling
  • Extreme panting
  • Vomiting
  • Diarrhea
  • Gums and tongue may turn dark pink or bright red

If you suspect your dog has become overheated, immediately cool the body using water from a pond, creek, hose or any other source to help bring down the body temperature. If your dog shows signs of heatstroke, you should take your dog immediately to the veterinarian. Negative results from advanced heatstroke can continue for 48 to 72 hours even if a dog appears normal, so it is important for a veterinarian to evaluate a dog for damage to the liver and kidneys and any other health problems.

Most dogs are very good at controlling their body temperature—until their temperature goes past a critical level. When this happens, even after a dog’s temperature is lowered back into the safe range, the dog may experience permanent inability to regulate its body temperature as well as it did before overheating.

Here are some tips to help you take the heat out of summer.

Hydration Tips

  • Monitor a working dog for signs of heat stress and dehydration.
  • To identify mild dehydration easily, lightly pinch the skin on your dog’s forehead. Skin on the top of the head is very sensitive to dehydration and should snap back into shape quickly if your dog is properly hydrated. Each pet owner should evaluate this when their pet is hydrated so they know what their dog’s ‘normal’ looks like.
  • To slow dehydration, a dog should be given small amounts of water every 15 to 20 minutes when working and especially during events lasting longer than 60 minutes.
  • Try cooling your dog by periodically squirting him or her with a spray bottle or mister. The wetness on the coat has a cooling effect as it evaporates.

Water Rules

  • Always give an overheated dog cool water rather than ice water, which could cause the dog to cool down too quickly. Ice water can cause blood vessels to constrict, which slows blood flow to the brain and the cooling process.
  • To boost water consumption, try baiting water with low-sodium chicken broth to encourage drinking or try mixing a few food kibbles with water and adding chicken broth.
  • Use running water—a faucet or hose—to wet down a dog’s body. Never submerge a dog in water, as this could cause a dog to cool too rapidly and lead to other problems.
  • After working, make sure a dog has access to water, but wait until a dog’s panting slows down before allowing the dog to drink a large volume of water.

Water as a Nutrient

Did you know that water is the most essential nutrient? This is because water supports many physiological functions, helps to remove metabolic waste and establishes a complex body-fluid matrix that underlies all metabolic processes.

At the Purina Companion Animal Nutrition Summit held in 2017 in Vancouver, Canada, Purina Senior Nutrition Scientist Brian Zanghi, PhD, explained that hydration is a dynamic process between water intake and loss in which there is no consensus on how to define optimal hydration in dogs.

“Many factors influence a dog’s daily water loss and hydration,” Dr. Zanghi says. “These include a dog’s environment, health condition, age, physical activity, water availability and diet. Without a doubt, a dog’s body water is in constant flux, thus regulation of water balance and thirst-driven water intake is necessary to replenish the persistent evaporative loss of water primarily through respiration, with smaller amounts from skin and coat, and urine, saliva and feces.”

The bottom line, Dr. Zanghi advises, is that “dogs should always have fresh water available to help establish true hydration.”

Dog’s Complex Circulation

A dog compensates for overheating by panting, which causes salivation. As saliva evaporates, it cools the blood going to the brain, helping to maintain central nervous system (CNS) functioning.

While panting is an effective short-term solution to help maintain CNS function, it is an inefficient method of lowering body temperature in the long run because it uses energy and generates additional heat.

About 60 percent of heat dissipated by dogs during exercise is through water evaporation in the respiratory tract.

In extreme conditions, a dog’s body redirects the flow of warm blood from the body core to vessels under the skin where it is cooled by air or water flowing over the skin.

The only place dogs sweat is around the pads of their paws.

How to Help an Overheated Dog

  • First, cool down your dog, and then work on restoring hydration.
  • Apply cool water to the foot pads.
  • Get the dog into shade out of direct sunlight.
  • If possible, try to keep the dog moving by encouraging standing or walking slowly. The circulating blood tends to pool in certain areas if a dog is lying down, thus preventing the cooled blood from circulating back to the core.
  • Allow the dog to drink small amounts of water, but do not let the dog gulp water, as drinking too much water too rapidly could cause vomiting.
  • Use cool water under the dog’s front legs and in the groin area where there is a higher concentration of large blood vessels to aid cooling.
  • Do not cover a dog with a wet towel or blanket, as you want to be sure the water can evaporate and this inhibits evaporation by creating a sauna effect.
  • After wetting down a dog, do not put the dog in an enclosed kennel, as this reduces air flow that would benefit the cooling process.
  • Sitting with a wet dog in a vehicle with the air conditioning blowing helps cooling.

Monitor Your Dog’s Temperature

Trainers should carry a rectal or ear thermometer that can be used during training. A dog’s body temperature is normally between 100 to 102.5 degrees. Take your dog’s temperature at the first sign of distress or after exercise. If it is above 104 degrees, start cooling down your dog right away.

Immediately after hard work, a sporting dog’s temperature may be as high as 107 degrees. Within five minutes, the temperature should decline to below 104 degrees. If a dog’s temperature remains above 104 degrees, the dog is likely suffering from heat stress and requires immediate veterinary care.