When your cat is ill, you may have to determine whether or not he has a fever. Learning how to take your cat's temperature properly can help determine if immediate veterinary care is needed.

Your cat's normal rectal temperature is 100.5 to 102.5 degrees Fahrenheit. Higher temperatures may necessitate a trip to your veterinarian, depending on other symptoms. Feeling the ears, nose or head is not considered a reliable method; you have to determine your cat's internal temperature to find out for certain. This is done rectally, using a rectal or oral thermometer, either digital or mercury. Ear thermometers can also be used in cats. They are generally fast and easy but it is essential to use a proper technique to obtain an accurate temperature reading.

Instructions for Rectal Temperatures

Some cats will allow you to take their temperature, but others don't like it at all. It might be easier if you get another person to assist by holding your cat firmly in a standing position. You can place her head in the crook of the arm and face her outward. If necessary, wrap your pet in a towel with the tail area exposed. Then do the following:

If using a mercury thermometer, remember to shake it with a quick flick of the wrist until the mercury is below 94 degrees. Then lubricate the thermometer with petroleum jelly, KY jelly or other water-based lubricant.

Have your helper gently grab the skin at the base of the neck to "scruff" the cat while holding the front legs still.

Lift your cat's tail and insert the thermometer slowly and carefully into the rectum, located just below the base of the tail. Insert the thermometer about 1 inch and hold in place – two minutes for mercury thermometers or until the digital thermometer beeps.

Remove the thermometer and read the temperature.

Instructions for Ear Temperatures

The normal ear temperature in cats is between 100.0 degrees and 103.0 degrees Fahrenheit (37.8 degrees and 39.4 degrees Celsius). The ear thermometer works by measuring infrared heat waves that come from the ear drum area. The ear drum is considered to be a good indicator of body temperature as it measures brain blood temperature. It is important to place the thermometer deep into the horizontal ear canal to obtain an accurate reading. An ear thermometer such as the Pet-Temp® designed for cats and dogs works best due to a longer arm that allows for the probe to be placed deeper into the ear canal. The first few times you use it, take both an ear and rectal temperature and compare. The results should be very close if you are using the proper ear technique.

If your cat has a body temperature less than 99 degrees or over 104 degrees, contact your veterinarian or local emergency facility immediately. A high temperature could mean your cat has an infection. A temperature below normal can be just as serious, indicating other problems like shock.