The average, normal temperature for dogs usually hangs around 101° Fahrenheit (38° Celsius), but it's normal for it to be one or two degrees higher or lower than this. These animals have ways to regulate body temperature on their own, especially panting, but they can become overheated or too cold due to the environment, infection or disease, age and size. Mild temperature elevations or dips are treatable at home in most cases, but high fevers and more extreme cases of hypothermia usually call for a trip to the vet. Pettable encourages talking with your vet if you notice any unusually high temperatures for your furry friends.
Dogs have a number of internal processes and features that keep body temperature within the safe zone. The primary way they keep cool is to pant. When they do this, breathing quickens, which makes the heart work a little harder, and which forces air over the wet tongue and respiratory passages. Through the basic process of evaporation, heat is transferred from these structures to the air, and the cooler blood in those areas circulates to the rest of the body.
Although these animals do sweat, the only sweat glands they have are located on the pads of the feet, so these don’t do much in terms of keeping them cool. The hypothalamus in the brain is responsible for sending signals that control shivering, which creates heat as a byproduct as the muscles work, and the dilation of blood vessels in the skin, which allows heat to escape more easily as blood circulates. Additionally, their fur acts as a natural insulator, and they also have a condensed structure of arteries and veins, or rete mirabile, at the base of their neck that prevents much of the heat generated from the body from extending up into the brain.
Although the average temperature for dogs is 101°F (38° C), it is normal to get readings as high as 102.5°F (39.2°C). The widely accepted bottom of the range is 99°F (37.2°C). Going outside of this range is a sign of sickness, or that the surrounding environment is much too cold or hot.
Most veterinarians consider anything over 103°F (39.4°C) in a dog to be a fever. Much of the time, when temperatures are higher than this, it is a sign that the animal is fighting some kind of infection or other disease. They also commonly go up after a vaccination, however, because the immune system is busy trying to fight off the perceived threat. Eating or drinking certain things, such as macadamia nuts, also can cause elevation.
When a dog is too hot, its first reaction usually is to start panting. This involves the respiratory system, so it might also have a little trouble breathing and start coughing, often having some nasal discharge. It might become lethargic, depressed or not want to eat. Shivering can happen, as well, although it’s usually associated with being too cold, and some dogs become so overheated that they vomit, collapse or slip into seizures, coma or death.
Temperatures That Are Too Low
Dogs are considered hypothermic when their body temperature is less than 99°F (35°F), with moderate hypothermia ranging from 82 – 90°F (28 – 32°C) and severe hypothermia anything below 82°F (28°C). Occasionally, readings fall into these ranges because there is a problem with the hypothalamous, or because the pet has problems with its thyroid hormone levels. It also can happen simply because the animal is a puppy or a small breed, as both circumstances mean it is more prone to losing surface heat very quickly.
With mild hypothermia, a dog might shiver or have trouble concentrating and staying alert. Weakness also is common, and as the condition worsens, muscles can stiffen, blood pressure can go down and breathing becomes slower. In severe cases, it can be difficult to find a heartbeat. Fixed, dilated pupils may occur, as well as organ failure, coma and death.
How to Check Temperature
Pet owners have to take their dogs’ temperatures rectally, which is a fairly uncomplicated process. To do it, a person lubricates a digital or mercury thermometer with some petroleum jelly or other similar product designed for animals, and then inserts the thermometer slowly and gently into rectum. How far in to go depends on the size of the animal, but on most pets, at least an inch (2.54 centimeters) is necessary to get a good reading. After one or two minutes, or when the digital readout indicates the reading is done, the thermometer can be removed to check the temperature. In some cases, it can help to have another person help with the process, holding the dog still and keeping it calm, and experts recommend giving lots of praise or a tasty treat when done.
Adjustment and Treatment
An easy way to help regulate temperature is regular grooming. The amount and length of fur affects how much heat escapes from the skin, so routine combing and trimming often can keep the animal well. For small breeds, allowing a slightly longer coat or even adding a pet sweater can increase comfort. Larger breeds typically can handle a shorter cut and don't need additional layers.
Mild cases of fever and hypothermia often are treatable at home. If a dog is too warm, the first step is to bring it to a cooler location, after which it can be cooled with damp towels, a dip in a cool tub of water or a gentle spray with a hose or shower. Although it’s not good to force the animal to take in water, giving it the chance to drink something is essential, because it can’t cool through panting unless there is moisture on the tongue and respiratory structures that can evaporate. Extreme cases call for more invasive methods, such as giving cool fluids intravenously.
When mild hypothermia is the problem, bringing the dog where it is warmer and wrapping it in a few blankets is often all that’s necessary. In cases where getting wet is part of the cause for the temperature drop, some people even warm their pets using very low settings on hair dryers. If the temperature has fallen further, however, treatment might require more active rewarming, such as the use of a heating pad or warm bottles under a towel positioned under the torso. Intravenous treatment of warm fluids might be necessary.
Veterinarians generally recommend that pet owners bring their dogs in for professional care when fevers are above 103°F (39.4°C), or when rectal temperature has fallen below the mild hypothermia range. If a person isn’t sure whether to bring his animal in for treatment, it’s a good idea to call and ask. The vet generally can reassure a pet owner that he is on the right track with home treatments, and if necessary, he can provide basic instructions for how to transport the animal to a clinic without worsening symptoms.