Normal Resting Temperature of a Horse

Measuring Temperature

• The temperature of a horse is best measured by holding a thermometer tightly or securing it the tail with a string and inserting it rectally, according to Horses and Horse Information. The thermometer may be difficult to retrieve if it is not secured.

Baseline

• Measuring a horse's temperature at times when it is healthy helps establish its baseline reading, so that temperatures outside its normal range are more likely to indicate that something is wrong. Normal reading should not exceed 102 degrees.

High Readings

• Bacterial infections can raise temperatures from 102.5 to 103.5 degrees F. Later stages of viral infections can cause readings from 104.5 to over 105.5 degrees. If the horse has a biphasic fever, the reading may be normal in the morning, but spike higher later on.