You may have noticed how warm your dog feels when you’re cuddling with them. It’s not just your imagination: a dog’s normal body temperature is higher than ours.
Knowing how to take a dog’s temperature can tell you a lot about their health. As a dog owner, it’s important to know what equipment to use, where on the body to get an accurate temperature, and when a temperature indicates your dog needs veterinary attention.
What Is a Dog’s Normal Temperature?
On average, a normal dog’s temperature is 101.5°F. “Smaller-breed dogs have higher body temperatures than larger-breed dogs because their metabolism is a bit faster,” says Dr. Amy Attas, VMD. “A small dog with a temperature of 102°F doesn’t mean they’re sick.” Likewise, a temperature of 99°F doesn’t necessarily mean that a large dog is suffering ill effects.
The only way to get an accurate reading of a dog’s internal temperature is with a thermometer. Dr. Attas says you can use a human or dog thermometer since thermometers generally have temperature readings that are within a tenth of a point of each other. Accordingly, a normal body temperature for your dog might be 101.5°F one day and 101.2°F the next day. What she suggests is getting a baseline measurement for your dog by using the same thermometer each time you take their temperature.
If you haven’t taken your dog’s temperature, you might be wondering how to tell if a dog has a fever without a thermometer. One way to feel if their temperature is abnormal is by “touching your dog in places where they don’t have a lot of fur,” she says. For example, you can feel the underside of the ear or the groin area where the blood vessels are close to the surface. Other signs that your dog’s internal body temperature is elevated include:
- Looking distressed
- Eyes wide open
- Blood vessels visible in the whites of the eyes
- Skin feels hot to the touch
- Panting excessively
- Dark red gums
What Kind of Thermometer Do I Need?
There are different types of thermometers you can use to take your dog’s temperature. Mercury thermometers are made of glass and contain mercury. A dog digital thermometer uses heat sensors and can give you a reading in just a few seconds.
Aural Thermometer
Since dogs tend to be more sensitive about their rectal area compared to their ears, Dr. Attas’ first choice is to use a digital thermometer for dogs that goes inside the ear, called an aural thermometer. “When you look at an ear thermometer, the portion that goes into the ear has a slight bend to it,” she says. “You have to angle it in the direction of the ear canal.”
If you’re only touching the outer part of the ear, “that doesn’t tell you what the dog’s internal body temperature is,” she explains. “You have to go as deep as you possibly can into the canal and be comfortable using the thermometer.” If your dog has an ear infection, you won’t be able to get an accurate body temperature. In such cases, the next best option would be to use a rectal thermometer for dogs.
Rectal Thermometer
The only place you can use a mercury thermometer on dogs is in the rectum. However, if a dog is moving around, there’s a chance for the thermometer to break or get sucked inside the dog’s rectum, Dr. Attas explains. “In order for it to come out, the dog either has to have a bowel movement or you need to put a gloved finger inside to take it out,” she adds.
If you don’t feel comfortable taking an ear or rectal temperature, another option is placing the thermometer underneath your dog’s armpit, where there isn’t a lot of fur. “That’s a distant third choice for me,” Dr. Attas says, explaining that aural and rectal temperatures will give you a better idea of whether your dog’s temperature is abnormal.
Oral Thermometer
People commonly use an oral thermometer, mercury or digital, when taking their own temperature, but you should never put a thermometer inside a dog’s mouth. To get the best results, you would need to hold the thermometer under your dog’s tongue where the blood vessels are prominent. There’s a risk of injury if your dog bites your fingers or the thermometer.
Aside from broken glass, the mercury is toxic, so you don’t want it getting in contact with your dog’s skin or mucous membranes or having them ingest it, she says. Mercury poisoning can lead to breathing problems, as well as damage to the kidneys or nervous system.
How Do I Take My Dog’s Temperature?
Taking your dog’s temperature is a two-person job. One person should be “holding the dog close to you so that their head is between your shoulder and forearm,” Dr. Attas says. That way, you’ll have one arm supporting the dog and the other arm free to pet and comfort the dog. Having your arm underneath the dog’s belly will keep them from sitting down and will allow the other person to have a clear view of their ear or rectum. Here’s what she suggests for using the thermometer safely:
- Read the instructions for a dog digital thermometer
- Practice using an ear thermometer on your own ears before using it on your dog
- Write your dog’s name on the thermometer in permanent ink (to avoid any confusion)
- Purchase disposable sleeves that fit over the ear or rectal thermometer for dogs, so the thermometer remains clean between uses
- Use a lubricating jelly when inserting the thermometer
Digital thermometers must be calibrated (read the directions to find out how) to ensure accurate temperatures before use, so you’ll need to have your dog in place and be ready to insert the thermometer. Applying jelly around the anal area keeps it well-lubricated and can help ease your dog’s discomfort. Once you get a reading, you can pull the thermometer out and discard the plastic sleeve. The thermometer will be clean and dry, and you’ll be able to read the number immediately, Dr. Attas says.
When Should I Take My Dog to the Vet?
A high body temperature in a dog can indicate an emergency, Dr. Attas says. If your dog’s temperature rises above 104°F, they will need to go to the vet. Brachycephalic breeds like the Bulldog have difficulty staying cool during the summer. Their body temperature can rise rapidly if they’re out walking on a hot day. If this happens, your dog, “needs to be cooled down quickly but not too quickly,” she adds.
Start by offering them cool water. If your dog refuses to drink, you can put them in a cool water bath or place towels soaked with water on body parts with less fur. You can also put cool towels on the ground for them to lie down. “If their body temperature doesn’t come down quickly, these dogs need to go see a vet,” she says. “When they’re en route to the vet, especially when they have temperatures over 104°F, they should travel with cool towels or have a fan on them to bring down their temperature.”
You can also place a bag of frozen peas against them to cool their body. But it’s never a good idea to use ice cubes or place your dog in an ice bath to cool down. “Ice can cause the blood vessels to constrict and that might exacerbate the elevated body temperature,” she says. “Super-high temperatures for a very long period of time can be life-threatening, so you really have to bring their temperature down.”
Just as a dog’s temperature can be too high, it’s also concerning if it’s too low. “Typically, we see low body temperatures in dogs that are older, sick, or dehydrated,” she says. You can use blankets and a heat source to help increase their temperature. She suggests filling a tube sock with uncooked rice, tying it up, and microwaving it for 30 to 60 seconds. Shake the rice around and hold it against your skin to ensure it’s not too hot for your dog. If your dog’s temperature falls below 99°F, “you should seek veterinary care because it can be a sign of kidney infection or something else affecting their system.