Dog Fever Signs: How to Tell and What to Do

By Tailwisp Editorial TeamUpdated October 17, 20263 min read

Fever is a body response to illness, not a disease, and finding the cause is what matters.

Signs

• Lethargy and sleeping more
• Loss of appetite
• Shivering or trembling
• Warm or hot ears and paws
• Red or glassy eyes
• Panting
• Cough, runny nose or vomiting depending on cause
• Reluctance to move

A warm or dry nose does not reliably indicate fever.

Confirming with a thermometer

A rectal digital thermometer is the best way. See how to take a dog's temperature. Above about 103 F (39.4 C) is considered fever, and above 106 F (41.1 C) is life-threatening.

Types of fever

• True fever: the body's set point is raised by illness, such as infection or inflammation
• Hyperthermia: high temperature from external heat or exertion, such as heatstroke. See dog heatstroke

They need different handling, so a vet should assess.

Common causes

• Bacterial, viral and fungal infections
• Tick-borne disease. See Lyme disease in dogs
• Abscesses and wounds. See dog wounds and cuts
• Urinary and respiratory infections. See urinary tract infections in dogs
• Dental infections
• Immune-mediated diseases
• Cancer, such as lymphoma
• Toxins and medications
• Vaccine response, usually mild and brief. See dog vaccine reactions
• Pancreatitis and other inflammatory conditions

When to call the vet

Call your vet if your dog has a temperature above 103 F, a fever lasting more than a day, fever with vomiting, diarrhea, cough or lethargy, or if he is a puppy, senior or has other illness. Go to an emergency clinic for temperature above 104 F, seizures, collapse or breathing difficulty.

What not to do

• Do not give human fever reducers such as acetaminophen or ibuprofen. See why human painkillers are dangerous for dogs.
• Do not use ice baths.
• Do not ignore fever for days.

At-home comfort while you call

1. Offer fresh water.
2. Keep him comfortable in a cool, quiet room.
3. Place a cool, damp cloth on paws and ears if the fever is high and the cause may be heat.
4. Monitor temperature every few hours as advised.
5. Contact your vet.

What your vet may do

Expect an exam, bloodwork, urinalysis, X-rays and maybe tick or infection tests. Treatment depends on the cause, and may include antibiotics, fluids and pain relief.

Fever after vaccines

A mild fever and tiredness for a day after vaccines is common. Call your vet if it lasts more than a day or two or if other signs appear.

Questions to ask your vet

Ask how to monitor temperature, which signs mean urgent care and whether any medication is safe for comfort. Ask about causes in your region.

Common mistakes

• Relying on nose touch
• Giving human medication
• Waiting for days
• Not recording temperature

Troubleshooting

• My dog's temperature is 103 F but he looks fine: recheck and call your vet.
• The fever returns: book an exam.
• My dog is shivering and warm: take his temperature.

A simple plan

1. Take his temperature.
2. Look for other signs.
3. Call your vet.
4. Follow the plan.

Real-life examples

A spaniel with a 104 F fever and no appetite has a tick-borne infection and recovers on antibiotics. A terrier with a fever after vaccines improves in a day. A senior dog with a fever has a hidden abscess. Causes vary.

Take it seriously

Persistent fever needs a diagnosis.

The takeaway

Measure temperature, avoid human medication and call your vet for fever with other signs.

This article is general educational information, not veterinary advice. Every dog is different. If your dog is unwell, or you are unsure about a symptom, diet change or medication, contact your veterinarian.