A dog's body temperature runs significantly higher than a human's. A dog's normal body temperature can range from 99 degrees to 102.5 degrees Fahrenheit. Temperatures higher or lower than this normal range—known as hyperthermia or hypothermia, respectively—may be cause for concern. Knowing how to evaluate your dog's temperature can help you determine whether there is a problem that requires veterinary attention.

Veterinarian and dog owner at the vet with dog.

How to Take a Dog's Temperature

The most accurate way to take a dog's temperature is by gently inserting the thermometer into the dog's rectum. Make sure you do this only with a thermometer that will never be reused in a human patient! Pet-specific oral, ear, and skin thermometers are also available, but these may be inaccurate. If your dog's temperature is not within the range of 99–102.5 degrees Fahrenheit, you should contact your veterinarian for further advice. Your veterinarian may recommend bringing your dog in for an examination if the temperature change is significant.

What Causes Fever in Dogs?

There are many possible causes of fever in dogs. Mild elevations in body temperature can occur if a dog becomes excited or has been exercising. This is particularly common in brachycephalic—or short-nosed—breeds, such as Pugs, Boxers, and Bulldogs because these breeds cannot cool themselves as efficiently as other dogs.

Just like in people, dogs can also develop a fever if they are sick. Fever is a non-specific symptom, which means it occurs as a result of many different illnesses. Infections have the potential to cause a fever. Like humans, dogs experiencing a fever are often lethargic and may shiver, pant, and have a decreased appetite.

In hot weather, a dog experiencing heatstroke will also have an elevated body temperature. This is an emergency because heatstroke can progress rapidly and may lead to organ damage or even death if left untreated.

What Causes Hypothermia in Dogs?

Hypothermia is uncommon in healthy dogs under normal conditions. A dog's temperature can be low if he is exposed to cold environments for long periods of time, particularly in wet weather. Young puppies and geriatric dogs are much more susceptible to cold temperatures than healthy adults, so particular care should be taken with these individuals in the winter months. Hypothermia can also occur in patients undergoing anesthesia and surgery, or those exposed to certain infections or toxins.

What to Do If Your Dog's Temperature is Abnormal

A dog's temperature can fluctuate throughout the day based on activity level and environmental temperature, but any variations outside the normal range should be evaluated by your veterinarian. Your vet will likely perform a full physical examination and may recommend additional tests to identify the underlying cause of your dog's change in body temperature so that appropriate treatment can be prescribed.

In cases of heatstroke, studies have shown improved outcomes when cooling is started immediately, before transporting the pet to the veterinary clinic. Dousing your dog with cool water from a hose and perhaps placing him on a cooling bed while in the car can help bring his temperature down more quickly. However, don't delay; if there are no cooling options readily available, just focus on getting your dog to the nearest veterinary clinic as quickly as possible.