Ear Thermometer Vs. Rectal for a Dog

For dogs, ear thermometers work just the same as they do for you.
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Determining your dog's temperature at home is necessary from time to time -- if your dog is sick, for instance, or if the dog's pregnant and you want to know if labor's imminent. A drop in temperature near a gestating dog's due date signifies labor is less than a day away. The traditional method for taking a dog’s temperature is a rectal thermometer; newer ear thermometers are less invasive alternative.

Rectal Thermometers

A rectal thermometer is the most reliable way to take your dog’s temperature. Unfortunately, it can create a very difficult task, especially if you do not have an extra pair of hands to help. To take a rectal temperature, insert a rectal thermometer 1 to 3 inches into the rectum and keep in place for at least 2 minutes. Ideally, you want to lubricate the thermometer with petroleum jelly and, while another person holds your dog still, insert the thermometer. Normal rectal temperature is between 100.5 and 102 degrees Fahrenheit.

Ear Thermometers

Ear thermometers measure temperature through infrared heat waves that come from your dog’s eardrum. The thermometer must go deep inside the ear canal in order to get an accurate reading from the eardrum. Ear thermometers may be easier to use but, because of the importance of placement in the ear, the readings are not always accurate. Normal ear temperature is between 100 and 103 degrees Fahrenheit.