How to Tell if Your Dog Has a Fever

While it can be easy to tell if your dog isn’t feeling well, some signs and symptoms can be subtle and hard to spot. Fever in dogs, for example, needs one to be keen and know the signs to look for.

Below we highlight how to tell if your dog has a fever, the likely causes, and how to bring down their body temperature. But first, what is the normal body temperature of dogs?

How to Tell if Your Dog Has a Fever
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What is the normal temperature of a dog?

The normal body temperature of dogs ranges between 38°C to 39.2°C (100°F to 102.5°F). A dog is said to have a mild fever when its temperature is above 39.4°C (103°F) while a temperature above 40°C (104°F) is classified as a high fever. Temperatures over 41.1°C (106°F) are potentially life-threatening and may cause lasting damage to internal organs.

How to tell if your dog has a fever

The most common signs of fever in dogs you should be on the lookout for include;

1. High body temperature

The most accurate way to tell if your dog has a fever is to measure its body temperature. Using a rectal thermometer produces the most accurate readings but can be uncomfortable for you and your pup. Luckily, you can do it with the help of an experienced vet tech. Alternatively, you can use other thermometers that measure a dog’s temperature in the ear, mouth, or under the armpit.

If the readings indicate your dog’s body temperature is more than 103 degrees Fahrenheit, it is experiencing a fever. Please note that a body temperature of 106 degrees Fahrenheit can be fatal for dogs.

CAUTION: Most non-digital thermometers contain mercury inside a glass tube. Make sure your pet does not bite or break the thermometer because mercury is toxic to both pets and humans. Besides, broken glass can cause injuries to your dogs.

2. Shivering

If you notice your dog is shivering and cold isn’t the cause, the shivering could be caused by a fever. If you establish cold isn’t the cause, make sure your pet is in a well-aerated, cool place to help lower its body temperature.

3. Warm, dry nose

If your dog’s nose is dry and very warm, it could also be a sign of a fever. You can feel your dog’s nose with the back of your hand to tell if it is having an abnormally high body temperature.

4. Lethargy

Does your fluffy friend seem tired and disinterested in playing around? If you notice your dog is lethargic and less playful than usual, it could be a sign of fever. While your dog being lethargic doesn’t necessarily mean they have a fever, it’s important to examine them to know if they are feverish and whether the symptom is an indication of another illness or medical condition. You should consult your vet if your pup remains lethargic for long periods.

5. Red eyes

Another way to tell if your dog has a fever is to check its eyes. Redness in the eyes can be a sign of fever in dogs and is often caused by infections, irritation, allergies, pink eye, or influenza. If you notice your dog has red eyes, consult your vet so that your pup can be treated accordingly.

6. Nasal discharge

Nasal discharge is another symptom you should look out for. However, it’s important to know that a fever might not be the only reason your dog is exhibiting nasal discharge. Other possible causes include allergic irritation, kennel cough, and even cancer. That’s why consulting your vet is recommendable if your dog has nasal discharge to ensure it gets the right treatment.

7. Vomiting

Vomiting is another likely indicator that your dog has a fever. It is often a sign of gastrointestinal issues, and if accompanied by high body temperatures above 103 degrees Fahrenheit, it could be a sign of bacterial infection. In case your dog is vomiting a lot, you need to make sure it remains adequately hydrated, which could include the use of an IV for fluids.

8. Loss of appetite

A dog that has a fever will show little interest in food, including its favorite treats. While the loss of appetite by itself is not a sign of fever, a fever resulting from an illness may make your dog disinterested in food. Be sure to work with your vet to determine the cause of appetite loss and outline an ideal treatment plan.

9. Warm ears

Warm ears can also indicate your dog has a fever. If you suspect it has, feel its ears with the back of your hand. If they feel abnormally hot then it could be a sign of fever.

What causes fever in dogs?

How to tell if your dog has a fever
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Now that you know how to tell if your dog has a fever, do you know what causes the fever in dogs? There is a multitude of reasons your fluffy friend experiences heightened body temperatures, lack of appetite, and even shivering. While we are going to highlight the common causes of fever in dogs below, your vet can give you the best answer after examining your pet.

The most common causes of fever in dogs include infections such as UTI and ear infections, inflammations from autoimmune diseases and infected wounds, tick-borne illnesses such as Lyme disease, poisonous substances such as toxic food and human medications, and vaccines.

1. Infections

Common infections that can cause fever in dogs include;

  • Ear infection
  • Urinary tract infection (UTI)
  • Infected wounds and cuts
  • Infection of internal organs such as kidneys and liver

These infections are quite easy to treat using antibiotics. Make sure it’s your vet that prescribes the antibiotic to use.

2. Inflammation

Inflammations can also cause fevers in dogs, with autoimmune diseases, cancer, infected wounds, parasite bites, and abscessed teeth being at the forefront. Your vet will determine the cause of the inflammation and the ideal way to treat it.

3. Ingestion of toxic or poisonous substances

If your dog ingests something toxic it can get a fever as the toxins spread through the body. Common toxic substances include toxic plants, antifreeze, rat poison, human medications, and human foods that are toxic to dogs, including xylitol. If you suspect your dog has ingested a toxic substance, contact Pet Poison Helpline for assistance.

4. Tick-borne diseases

Ticks can cause Lyme disease in pets, including in cats and dogs. If you recently removed a tick on your dog or have been in a tick-infested area, and your pet is displaying fever symptoms, you should consult your vet.

5. Vaccines

There are instances when dogs experience a low-grade fever after receiving a vaccine. Luckily, it lasts between 24-48 hours. In case the fever does not break after 48 hours you should consult your vet.

How to reduce a dog’s fever

While there’s no single clear-cut way to lower a dog’s temperature when it has a fever, a combination of these strategies will help a great deal.

  • Soak pieces of cloth or a towel in cold water and place them around its paws and ears
  • Get your dog to drink plenty of fresh, cool water
  • Keep measuring its body temperature and when it drops below 39.4°C (103°F) you can stop applying a soaked towel or giving it water to drink.
  • In case the fever returns then take your dog to the vet as there could be an underlying cause of the fever.

CAUTION: Do not give human fever medications such as acetaminophen or Tylenol to dogs as these are toxic to them.


Although we have highlighted several signs and symptoms of fever in dogs, it’s important to note that one symptom alone might not mean the dog has a fever, but a combination of a few of these means you should get them checked by a vet.