How to Tell if Your Dog Has a Fever

Common Signs of Fever in Dogs

If your dog’s temperature exceeds 39.5°C then it has a fever.  The fever itself is a clinical sign that tells us that something is not quite right with the dog. However, more investigations are needed to find out what may be causing the fever.

Other typical signs associated with a fever include:

•         Low energy levels or unusual behaviour
•         Lethargy
•         Decreased appetite
•         Panting or increased respiratory rate
•         Increased thirst
•         Shivering

Good to Know

You cannot determine a dog’s temperature by feeling its nose, paws, or ears. A rectal thermometer is the only accurate method.

What Causes a Fever in Dogs?

Fever can result from various health issues, including:

• Infections – both viral or bacterial, such as kennel cough, pyometra (uterine infection), infected wounds, or mastitis 
• Autoimmune diseases – like meningitis or polyarthritis
• Certain types of cancer

Fever in Puppies

Young dogs often show clearer signs of fever, such as fatigue and loss of appetite and a fever in a young puppy should always be taken seriously.

How to Take Your Dog’s Temperature

Measuring your dog’s temperature is the only way to know for sure if it has a fever.

1. Use a digital rectal thermometer
2. Apply lubricant (like petroleum jelly) to the tip
3. Have someone help hold your dog still
4. Let your dog stand or lie on its side
5. Gently insert the thermometer into the rectum
6. Wait for the beep and read the result
7. Reward your dog with praise or a treat to make the experience positive

Tip: To recognise fever in the future, familiarise yourself with your dog’s normal temperature when it’s healthy. Try practicing with the thermometer a few times at the same time of day when your dog is calm. Offer praise to keep the experience stress-free. This preparation makes it easier when your dog is sick or during a vet visit.

What Can I Do at Home?

If you suspect your dog has a fever:

• Take its temperature
• Let it rest in a cool, quiet space
• Provide fresh drinking water
• Monitor whether the fever rises, drops, or is accompanied by other symptoms like vomiting or diarrhoea.

You can also contact a veterinary helpline for advice on next steps 

When Should I Call the Vet?

Contact a vet if:

• Your dog’s temperature exceeds 39.5°C and lasts longer than 24 hours
• Your dog has a fever and shows signs of being generally unwell, such as being off food, not drinking, vomiting, having a persistent cough or breathing issues
• If your dog is a female with a vulval discharge
• Your dog seems in pain, is very lethargic, or isn’t responding normally

How Is a Dog’s Fever Treated?

At the clinic, your vet will perform an exam to determine the cause of the fever. Treatment depends on the underlying condition and may include:

• Anti-inflammatory or fever-reducing medications
• Fluid therapy if your dog is dehydrated or not drinking
• Antibiotics in some cases

Heatstroke in Dogs

The dog's body temperature can also rise above the normal level due to the dog being left in a hot environment for too long. This increase in temperature is called hyperthermia because the cause is external and not internal as we see it with dogs developing a fever. Dogs are vulnerable to heatstroke because they don’t sweat like us humans. The body temperature can rise to very dangerous and even fatal levels during a heatstroke and it is therefore always a medical emergency.

Click here to find out what to do if your dog has heatstroke.