Dog Temperature: Normal Range, Fever and How to Check

TL;DR: A normal dog temperature is 99.5 to 102.5°F (37.5 to 39.2°C), measured rectally at rest. 103°F (39.4°C) is a fever, anything above 104°F (40°C) or below 99°F (37.2°C) needs your vet, and 106°F (41.1°C) is an emergency. Only a thermometer can tell you. The nose can't.

Dogs run hotter than we do, so a dog that feels warm under your hand is usually just a dog. The useful question is not "does my dog feel hot?" but "what does the thermometer say, and what does that number mean?"

This guide gives you the ranges from the veterinary references, a puppy table most guides skip, a calm way to take a reading at home, and an honest look at ear thermometers. It also covers the one habit we picked up with Rocket, our lab, that makes every later reading easier to judge.

What is a normal temperature for a dog?

The Merck Veterinary Manual gives a normal rectal temperature for dogs of 99.5 to 102.5°F (37.5 to 39.2°C). The AKC uses the same range. VCA Animal Hospitals quotes a slightly narrower 100.0 to 102.5°F (37.7 to 39.2°C). Most healthy adult dogs sit near the middle, around 101°F, which is why the old "about 101" rule of thumb works.

Here is how to read the number on the thermometer for an adult dog at rest:

The thresholds come from the AKC (fever at 103°F, danger at 106°F) and VCA (vet visit above 104°F or below 99°F). The "measure again" row is our own habit, not a veterinary cutoff: a single high-normal reading right after excitement is not worth panicking over, but a second one at rest gives you a cleaner answer.

Normal temperature for puppies, by age

Newborn puppies cannot control their body heat well, and their normal is lower. The Merck Veterinary Manual lists:

So a 97°F reading means very different things in a five-day-old puppy and a five-year-old dog. If you are raising a litter, keep the whelping area warm, and treat a newborn that feels cold, cries constantly, or stops nursing as a reason to call the vet. For older puppies heading outdoors for the first time, see when a puppy can go outside.

How to take your dog's temperature at home

A digital rectal thermometer is the most accurate tool you can use at home. VCA calls it a two-person job: one person comforts and holds the dog, the other handles the thermometer. Our routine:

1. Pick the right thermometer. A basic digital one that beeps when done. Label it for the dog and never use it on people. VCA advises against glass mercury thermometers because they can break.
2. Get your dog lying on its side on a bed or rug, with your helper at the head and a few high-value treats ready.
3. Lubricate the tip with petroleum jelly.
4. Lift the tail and slide the thermometer in gently until the metal tip is fully inside, as VCA describes. Aim along the line of the spine, and if your dog clenches, stop. Never force it.
5. Hold the end steady until it beeps. A glass thermometer needs about two minutes.
6. Read, write it down with the time, and clean the thermometer with soap and water or an alcohol wipe.

Measure when your dog has been resting for a while, not straight after a run, a game of fetch, or a warm car ride. You want to compare like with like.

What we do with Rocket: we took a few readings on calm, healthy days and wrote down the average. Rocket's own normal is now a number on the fridge, so when he seems off we are comparing against his baseline, not a textbook range. It takes two minutes and saves a lot of guessing at 11 p.m.

Are ear thermometers accurate for dogs?

Ear thermometers made for pets are faster and many dogs tolerate them better. VCA says to place them at 90 degrees to the head into the horizontal part of the ear canal, and warns that an infected, painful ear gives inaccurate readings.

The catch is accuracy. A 2023 study in Veterinary Medicine: Research and Reports compared ear and rectal readings in 152 dogs brought to an emergency room. Ear readings were on average about 0.6°F (0.36°C) lower than rectal ones, and in individual dogs the difference stretched past 3°F (1.7°C). The authors concluded that ear thermometry may not be acceptable for emergency patients, especially dogs that were too hot or too cold, which is exactly when the number matters most.

Our take: an ear thermometer is fine for spotting a trend in a dog you already know well. When the reading will decide whether you drive to the emergency clinic, use a rectal one.

Why does a dog's temperature go up?

A rise in temperature has two very different families of causes, and the treatment is opposite.

• Overheating (hyperthermia). Heat, humidity, hard exercise, or a hot car push the temperature up from the outside. This is how heatstroke starts. It is the main risk for active dogs and why we keep runs short and early on warm days; see the signs of heatstroke in dogs for the first-aid steps.
• Fever. The body raises its own set point to fight something. The AKC lists causes such as infected wounds, ear infections, urinary tract infections, abscessed teeth, and bacterial or viral disease, as well as poisoning from things like antifreeze, toxic plants, human medications, and foods containing xylitol.

Context usually tells you which one you are looking at. A dog that is hot after a summer run and pants hard needs cooling. A dog that is hot on the couch, off its food, and quiet probably has a fever. Panting at rest is worth reading up on in our guide to why dogs pant.

Signs your dog may have a fever

Many dogs with a fever just look "not right". The AKC lists these signs:

• Red eyes
• Lethargy and low energy (see why your dog might be lethargic)
• Warm ears and a warm, dry nose
• Shivering
• Loss of appetite
• Coughing
• Vomiting

None of these confirms a fever on its own, and the AKC is clear that the nose test alone often isn't enough. If you see two or three together, take a reading.

When to call your vet

Call your vet, or go to an emergency clinic if yours is closed, when:

• The rectal reading is 103°F (39.4°C) or higher, especially with any of the signs above.
• The reading is above 104°F (40°C) or below 99°F (37.2°C). VCA treats both as reasons to see the vet.
• The reading is 106°F (41.1°C) or higher. The AKC warns this can damage internal organs and be fatal. Go now.
• Your dog collapses, wobbles, or pants frantically after heat or exercise, whatever the thermometer says.
• A newborn puppy feels cold or stops nursing.

Do not give your dog acetaminophen, ibuprofen, or any other human fever medication. The AKC is firm: never give your dog human medications without consulting a veterinarian first, and some are toxic to dogs.

Mistakes we see all the time

• Judging by the nose. Warm and dry is not a diagnosis. Neither is cold and wet.
• Measuring straight after exercise and reading a normal post-run rise as a fever.
• Trusting a low ear reading in a dog that looks unwell. Confirm rectally.
• Using the family thermometer. Keep one for the dog only.
• Not knowing your dog's normal. A baseline taken on a good day makes every future reading easier to judge.

In short

A normal dog temperature is 99.5 to 102.5°F (37.5 to 39.2°C), fever starts at 103°F, and 106°F is an emergency. Use a digital rectal thermometer with a helper, measure at rest, and write down your dog's own normal on a healthy day. Temperature works best alongside your dog's other vital signs: a normal heart rate for a dog and a normal breathing rate round out the picture.

A dog running a fever usually moves less and rests more before you ever reach for a thermometer. Rocket, the activity tracker we are building, is designed to make that kind of change in your dog's day easy to spot, and you can join the waitlist to hear when it is ready.