How to Tell if a Dog Has a Fever

Medical articles
dog laying under blanket with mug between hands

Can Dogs Get Fevers?

Dogs can get fevers just like people. A fever is an increase in body temperature above the normal range. It may also be called hyperthermia. A dog’s normal temperature ranges from 99.5°F to 102.5°F, with 100-101°F being most common. As with people, some dogs will have slightly cooler or slightly warmer than average temperatures, so it will be important to also assess a dog for common causes of fever if their temperature is not normal.

Causes of Fever in Dogs

Dogs can develop a fever for many reasons. The most concerning cause of a fever is infection (>103°F). Symptoms will depend on where the infection is. For example, a dog with an upper respiratory tract infection (e.g. doggy cold) may have a runny nose, watery eyes, and sneeze or cough in addition to his fever.

Another cause of fever is being overheated. Mild overheating can occur after running around the yard and playing hard. Panting and drinking a lot of water are common signs in addition to a slightly high temperature (e.g. 103.5°F). The temperature should go back to normal quickly once the dog is calm and resting in a cool environment. Severe overheating, also known as heat stroke, can cause a very high increase in temperature (>104°F). Stumbling or trouble walking, collapse, and trouble breathing may be seen.

Other causes of fever include contact with certain toxins/drugs, prolonged seizures, anaphylactic reactions (e.g. allergic reaction), envenomation (e.g. reptile/insect bite or stings), or severe inflammation.

Wet Nose vs Dry Nose Debate

While it is true that a dog’s nose can be dry and warm if he has a fever, this is not always the case. Some dogs can be sick and have a cool, wet nose. Other dogs with a warm, dry nose are healthy. A dog’s nose temperature and moisture can change throughout the day for many normal reasons like humidity and environmental temperature. This means that, unfortunately, checking the nose is not a reliable or accurate way to tell if a dog has a fever.

How to Take a Dog’s Temperature

The best way to take a dog’s temperature is to check it rectally with a thermometer. Any quick-read, digital thermometer will work. It is very important to designate and label this thermometer for dog use so that it isn’t accidentally used for people in the future. Make sure to lubricate the thermometer with either petroleum jelly or a water-based lubricant.

Checking a dog’s temperature orally is almost always inaccurate. Dogs have trouble holding still long enough to properly position a thermometer under their tongue with their mouths closed to achieve a reading.

Canine ear thermometers can be used, but these too are often inaccurate. Typically, ear thermometers show lower results than the dog’s true current temperature.

Other Ways to Check for Fever

If using a thermometer is not an option, temperature can sometimes be assessed by feeling the hairless parts of the skin, such as the belly and armpits. It helps to be very familiar with your dog’s normal skin temperature. If he seems hotter in these areas than normal, he may have a fever. This is a pretty inaccurate method, but it can help you decide if he needs to be checked by a veterinarian. Usually he will be showing other symptoms of illness to help reinforce the need for a vet visit.

What to Do Next

If your dog has a fever, he will need to be checked by a veterinarian. If you can’t get him in for a visit immediately, keep him hydrated by offering plenty of clean water and low sodium chicken broth. Keep him calm and in a cool (but not cold) area. If his temperature is very high, cool him down by rinsing him with room temperature water. Do not use ice cubes or very cold water because this may lower his temperature too quickly. Do not give aspirin or any other fever-reducing medicines normally prescribed for people. These medications can make dogs sicker. When you arrive for the veterinary appointment, make sure to let the veterinarian know what his temperature was, his symptoms, and what you did to try to reduce the fever.