Does My Dog Have a Fever? Normal Temperature, Signs and What to Do

Last updated: November 2025

What temperature counts as a fever in a dog?

Dogs run warmer than people. The Merck Veterinary Manual lists an average body temperature of 101 to 102.5°F for dogs, compared with about 98.6°F for us. That is why your dog can feel toasty in your lap and still be perfectly healthy.

Normal is a range, not a single number. The American Kennel Club puts the average at about 101.5°F and notes that small breeds tend to run a little warmer than large ones because their metabolism is faster. Veterinarian Dr. Amy Attas told the AKC that a small dog reading 102°F is not necessarily sick, and a large dog at 99°F is not automatically in trouble either.

A fever starts above that normal band. The AKC says a dog is considered to have a fever at 103°F or higher, and that 106°F or higher can damage internal organs and can be fatal. PetMD, in an article reviewed by a board-certified internal medicine vet, treats anything above 102.5°F as elevated and worth a vet visit.

A true fever is not just “being hot.” The brain has a thermostat, the hypothalamus, and during a fever it resets itself to a higher number on purpose, usually to fight an infection or inflammation. Merck notes that the fever itself may even help the body fight infection.

Excitement, exercise or a warm room can bump a reading up, so one slightly high number in a wriggly, excited dog is not the full story.

What do different dog temperatures mean?

Use this table as a quick guide for rectal readings. It is not a diagnosis. How your dog is acting matters as much as the number, so a dog that is collapsed, struggling to breathe or vomiting repeatedly needs a vet now whatever the thermometer says.

The ranges come from the Merck Veterinary Manual and the AKC. The “below 99°F” row follows Dr. Attas’s advice in the AKC: a temperature that low can point to an infection or another problem affecting the whole body. A dog that is cold after a winter walk is a different story. Our guide on how to keep a dog warm at night covers beds, blankets and safe room temperatures.

Does a warm, dry nose mean a dog has a fever?

No. The old “cold, wet nose means a healthy dog” rule is one of the most stubborn myths in pet care, and vets have been trying to retire it for years. The AKC points out that sick dogs can have wet noses too, and a Texas A&M vet calls the old belief simply not true across the board.

A nose turns warm and dry for everyday reasons. The AKC notes that sleeping dogs don’t lick their noses, and that exercise, sun, wind, a nearby heater and age can all dry it out.

“Usually, a dry nose on its own is not concerning unless the nose appears cracked, painful, or there is a dramatic change in its appearance, such as a change in color or going from bumpy to smooth.”

Dr. Erin Ray, Clinical Assistant Professor, Texas A&M College of Veterinary Medicine & Biomedical Sciences (Pet Talk, 2022)

The same goes for warm ears and a warm belly. A dog’s normal temperature is already higher than yours, so almost every dog feels warm to your hand. PetMD notes that you can’t detect a fever by touching a dog’s skin.

So what should you look at instead? The whole dog. Signs that often go along with a fever include:

• Low energy or lethargy
• Loss of appetite
• Shivering
• Red eyes
• Warm ears (together with other signs)
• Coughing
• Vomiting

That list comes from the AKC. Each sign can have other causes, which is why the thermometer matters. Shivering, for example, can come from cold, fear or pain as well as fever, as we explain in why is my dog shaking.

How do you take a dog’s temperature at home?

A rectal temperature with a digital thermometer is the most accurate way to check for a fever at home. Most dogs put up with it for the few seconds it takes. Here is the method, step by step.

First, get the right tool. Use a digital thermometer, either one made for pets or a regular human digital thermometer that you set aside for your dog only. The AKC warns against glass thermometers. Glass can break if your dog moves, and the old mercury kind contain a toxic metal. Never take a temperature in your dog’s mouth, because your dog can bite down on the thermometer or your fingers. Dr. Attas suggests writing your dog’s name on the thermometer in permanent marker so nobody in the house mixes it up, and buying disposable sleeves to keep it clean between uses. A dedicated thermometer belongs in your pet first aid kit along with the lubricant.

Second, recruit a helper. The AKC calls this a two-person job. The helper holds the dog close, with the dog’s head between their shoulder and forearm. One arm goes under your dog’s belly so your dog can’t sit down, and the other hand is free to pet and soothe. Let your dog settle for a few minutes first, since running around and excitement can raise the reading.

Third, lubricate. Coat the tip of the thermometer, or the sleeve, with petroleum jelly, a water-based lubricant or baby oil. Turn the thermometer on before you start so it is ready to read.

Fourth, insert gently. Lift your dog’s tail and slide the tip slowly into the anus about one inch. In very small dogs, a little less is plenty. Do not force it. If you feel resistance, stop, wait and try again with a slight change of angle. Hold the thermometer steady the whole time so it can’t slip in further or fall out.

Fifth, wait for the beep. Many pet thermometers read in under a minute, and the AKC notes some register in about 60 seconds. Keep your voice calm.

Sixth, remove, read and record. Slide the thermometer out, read the number and write it down with the time. A reading taken at 8 a.m. and another at 2 p.m. tell your vet much more than a single number. Then toss the sleeve or wash the tip with soap and warm water and wipe it with rubbing alcohol before you put it away.

If the first reading is slightly high and your dog has just been playing, rested for a bit in a cool room and recheck. If it is high again, or if your dog seems unwell, call your vet with both numbers. If your dog fights hard, growls or snaps, stop. A frightened dog can hurt itself or you. PetMD notes that this is sometimes best done at the vet clinic, and there is no shame in letting the professionals do it.

One more thing. PetMD points out that there is no benefit to taking your healthy dog’s temperature on a regular schedule, because activity, stress and warm weather all nudge it up. Save the thermometer for when your dog seems off, plus a few calm readings to learn your dog’s normal baseline.

Are ear thermometers accurate for dogs?

Ear thermometers are quicker and many dogs tolerate them better, but the research says they are less accurate than a rectal reading, especially when a dog is sick.

In a 2023 study in the journal Veterinary Medicine: Research and Reports, emergency vets checked 152 dogs with both an ear thermometer and a rectal thermometer. Ear readings averaged 38.3°C (about 100.9°F), while rectal readings averaged 38.7°C (about 101.7°F). In dogs with a high temperature, ear readings were about 0.66°C (roughly 1.2°F) lower on average, and the two methods did not track each other reliably. The authors concluded that ear thermometry may not be acceptable for dogs coming into the emergency room.

The gap matters most in the dogs you worry about. About 30% of the dogs in that study arrived with an abnormal temperature, and for those dogs the ear reading was not a good stand-in for the rectal one. A low ear reading could talk you out of a call you should make.

Technique is part of the problem. Dr. Attas, who likes ear thermometers for comfort, says the probe has to go deep into the ear canal, angled the right way, or it only measures the outer ear. An ear infection also throws the reading off, and then a rectal thermometer is the better choice.

Underarm readings are another option some owners try. Dr. Attas calls the armpit a “distant third choice” behind ear and rectal readings.

What causes a fever in dogs?

A fever is a symptom, not a disease. It means your dog’s immune system is responding to something. According to the Merck Veterinary Manual, fever can point to infection, inflammation, an immune-mediated disease or cancer.

Infections. Bacteria, viruses and fungi are classic triggers. That includes a respiratory infection such as kennel cough, an infected wound or bite, a tooth abscess, a urinary or kidney infection, or a tick-borne illness.

Inflammation and immune problems. Sometimes the body’s own immune system attacks its joints, blood cells or other tissue. In a 2012 study of 50 feverish dogs that Merck summarizes, 48% had a noninfectious inflammatory disease, including immune-mediated conditions, while 18% had an infection and 6% had cancer.

Vaccine reactions. A mild fever can follow vaccines. The American Veterinary Medical Association lists mild fever, tiredness, a smaller appetite and a sore injection spot as common, short-lived side effects that usually pass within 24 hours. Call your vet if they last more than a day or two.

Toxins. Some poisonous plants, chemicals and medicines can raise body temperature. If your dog may have swallowed something, read our guide on what to do when your dog ate something it shouldn’t and call your vet or Pet Poison Helpline at 855-764-7661 (fees apply).

Fever of unknown origin. Sometimes the cause stays hidden after the first round of tests. Vets call this FUO. Merck explains that working it out can take repeated exams and many tests. In that same 50-dog study, 28% never got a definitive diagnosis, mostly because owners chose not to keep testing.

To help your vet, note when the fever started and any recent vaccines, bites, ticks, travel or chewing.

Is it a fever or heatstroke?

Both make a dog hot, but they are not the same thing, and the first aid is opposite. In a fever, the brain raises its own thermostat on purpose. In heatstroke, the thermostat is normal, but the body can’t get rid of heat fast enough. Merck explains that heatstroke, seizures and similar conditions can push a dog to 106°F or higher, above the range of most true fevers.

The clue is usually the situation. Heatstroke follows heat or hard exercise: a parked car, a hot afternoon walk, a game of fetch in humid weather. Flat-faced, older and overweight dogs are at higher risk, according to Cornell University’s College of Veterinary Medicine, and signs include heavy panting, drooling, vomiting, bloody diarrhea, weakness, confusion, seizures and collapse.

A feverish dog, on the other hand, tends to look quietly sick. It is tired, off its food, maybe shivering, and often there is no heat exposure to explain it. Panting can happen with both; our guide on why dogs pant so much helps sort out.

Heatstroke needs cooling right away. The Royal Veterinary College urges owners to “cool first, transport second.” Move your dog to shade or air conditioning, soak your dog with cool water and add moving air from a fan or the car’s air conditioning, then get to a vet. Skip ice-cold water, which can reduce blood flow to the skin. Speed matters. RVC research found that 97% of dogs treated for mild heat-related illness survived, compared with 43% of dogs with severe heatstroke.

Can you give a dog Tylenol or ibuprofen for a fever?

No. Never give your dog human fever or pain medicine unless your vet has prescribed it.

Pet Poison Helpline says nearly half of all the calls it receives involve human medications. At the top of its list are NSAIDs, the family that includes ibuprofen (Advil, Motrin) and naproxen (Aleve). The helpline warns that even one or two pills can seriously harm a pet, causing stomach and intestinal ulcers and kidney failure.

Acetaminophen (Tylenol) is not a safe swap. Pet Poison Helpline explains that acetaminophen leads to liver failure and, in large doses, damage to red blood cells, which carry oxygen around the body. Aspirin, too, should only be given on a vet’s instructions.

The helpline also warns that pets process medications very differently from people, and that a medicine being safe for children does not make it safe for animals.

A fever is also a clue. Masking it with medicine can hide how sick your dog is and make the cause harder to find.

If your dog has already swallowed a human medication, call your vet or Pet Poison Helpline at 855-764-7661 right away, or the ASPCA Animal Poison Control Center at 888-426-4435. Fees may apply. Keep the package so you can read out the exact ingredients and strength.

When is a dog’s fever an emergency?

Call your vet the same day for any rectal reading of 103°F or higher. Go to a vet or emergency clinic now, without waiting for an appointment, if any of these apply:

• A temperature of 104°F or higher, or 106°F at any point
• Collapse, severe weakness or trouble standing
• Trouble breathing, or blue, gray or very pale gums
• Seizures or confusion
• Repeated vomiting, or blood in vomit or stool
• Possible heatstroke or a known toxin
• Facial swelling, hives or collapse after a vaccine
• A puppy, senior dog or a dog with a chronic illness that runs a fever

These red flags come from the AKC, PetMD, Cornell and the AVMA. PetMD considers a fever above 104.5°F, or a fever with extreme lethargy, blood in the stool or vomit, or refusal to eat, an emergency. A mild fever lasting more than a day deserves a call too. If vomiting is the main problem, our guide on why your dog is throwing up covers the warning signs.

Plan ahead: save your vet and the nearest 24-hour clinic in your phone, and keep a thermometer in the first aid kit.

It also helps to keep your dog’s key health details where others can find them. In the free Lohji app, on the App Store and Google Play, you can add medical notes, your veterinarian and up to three contacts to the profile linked to your dog’s Smart Tag. If a pet sitter, neighbor or stranger finds your dog unwell, one tap on the tag with a phone shows them who to call. The tag is an NFC ID tag, not a GPS tracker, and it does not monitor health.

Frequently asked questions