Taking Your Pet’s Temperature

What is a normal temperature in dogs and cats?

Normal body temperature for humans is 98.6°F (37°C). Normal body temperature for dogs and cats is 100.0°F to 103.8°F (37.7°C to 39.8°C). Some people and pets maintain a baseline temperature a little above or below average, but if your pet’s temperature rises above 104°F (40.0°C) or falls below 99°F (37.2°C), take them to your veterinarian.

What are the signs of an abnormal temperature? 

Unfortunately, there is no easy checklist of signs that indicate high (hyperthermic) or low (hypothermic) body temperatures, but here are some general signs to look for: 

• Hypothermic pets may be lethargic and less alert. They may shiver or tremble.
• Hyperthermic pets may also be lethargic. They often pant to get rid of excess body heat, and their gums may become dark red.

Since these signs can occur with many medical problems, it is not possible for you to determine if your pet is hypothermic or hyperthermic just by looking at them; you must take their temperature.

What types of thermometers can I use for my pet?

There are two popular types of thermometers: digital and rectal. Digital thermometers are placed into the ear canal and rectal thermometers are inserted into the rectum. However, dogs and cats often resist both options, so taking a temperature can be challenging.

Old-fashioned rectal thermometers contain mercury inside a glass cylinder. The mercury is shaken down into the thermometer bulb, expands when heated, and rises into the calibrated cylinder to indicate the temperature. Reading the thermometer can be tricky but rolling it back and forth horizontally helps display the silver column of mercury. 

Glass thermometers are easy to break and require careful clean up if they break, since exposure to mercury is hazardous.  For these reasons, glass thermometers are not recommended. A digital thermometer used normally for a person under the tongue can be used rectally in a pet.

Digital thermometers have an easy-to-read numerical display in either Fahrenheit or Celsius. They calibrate themselves after being turned on. Digital ear thermometers are inserted into the ear canal and must be close to the ear drum to get an accurate reading. These readings are reasonably accurate, but not always precise, due to the many sizes and shapes of dogs’ and cats’ ear canals, plus the presence of hair, wax, and debris in the ear canal.

How can I take my pet's temperature?

Regardless of which thermometer you use, taking your pet’s temperature may be a two-person task. One person can hug your pet to provide comfort and restraint simultaneously. Cats and small dogs can be held in the lap with one arm placed under the neck holding the head snug against your body. The other arm can be placed around the abdomen to keep the pet still. Large dogs can be held in a similar manner, on the floor.  It can also be helpful to feed your pet a high-value treat or snack during the process to help distract them or lower their stress.

"Regardless of which thermometer you use, 
taking your pet’s temperature may be a two-person task."

When using a digital ear thermometer, you can allow your pet to stand up. When using a rectal thermometer, it is best to lie the pet down on their side before inserting the thermometer. If you insert a rectal thermometer while a pet is standing, they will likely sit down on the thermometer.

Rectal Technique

Lubricate the tip of the thermometer with petroleum jelly to ease insertion. Insert the thermometer until the metal tip is completely in the rectum. Hold the end of the thermometer to steady it and make retraction easier. 

If you feel stool in the rectum, try to place thermometer around the fecal matter rather than through it, to ensure an accurate reading. If the pet clamps their anal sphincter, do not force the thermometer into the rectum to avoid injury and pain for the pet.

If you must use a glass thermometer, insert it 1-2 inches and leave the thermometer in place for two minutes. A digital thermometer will usually beep when the temperature is ready to be read. Remove the thermometer and wipe it clean with a tissue before you read it.

Digital Ear Technique

Turn the thermometer on and allow it to calibrate. Many digital thermometers beep when calibrated and beep again when ready to read. No lubrication is needed prior to inserting the thermometer into the ear canal. Hold it at a 90-degree angle with the pet’s head, and insert the thermometer gently into the horizontal ear canal. 

If your pet resists, do not force the device into the ear canal. An infected ear is sore and inserting a thermometer will be painful. Additionally, using an ear thermometer on a dog or cat with an ear infection will produce slightly inaccurate readings.

If taking your pet’s temperature is difficult, do not risk injury to them or to yourself. Allow trained professionals to accurately and safely take their temperature at your veterinary hospital.

What should I do if my pet's temperature is higher or lower than normal?

First, double check all abnormal (high or low) temperature readings. Falsely elevated temperatures occur when pets are over-excited or agitated. Dogs and cats that resist restraint may have high temperatures that do not really qualify as a “fever”. Let the pet rest for 10 minutes, calm them down, and try again.

If your pet’s temperature is too low, the thermometer may have been inserted inappropriately. An abnormally low temperature may result when the thermometer is not inserted far enough in the ear or when it is embedded in feces in the rectum.

After rechecking, if your pet’s temperature is still moderately elevated (above 103.5°F or 39.7 C), give them a small amount of water or ice chips. Apply cool, damp cloths to the paws and place them in a ventilated area. If your pet’s temperature is too low, wrap them in warm towels or blankets. Hot water bottles may help but avoid heating pads, which can cause burns. If your pet’s temperature remains high or low, see your veterinarian. Remember that temperatures above 104°F (40°C) or below 99°F (37.2°C) are emergency situations.