Description
Pyrexia means fever, which means an increase in body temperature above normal. The "normal" body temperature range may vary depending upon the method of measurement used. The most widely used method is to take the temperature using a mercury thermometer inserted into the animal's rectum although other orifices can be used (e.g. the vagina). Recently modern technological developments have lead to the use of monitors which are inserted into the external ear canal.

Method for taking body temperature with a mercury thermometer
The rectum should be clear of feces, and the mercury must be shaken down to the bulb end of the thermometer before inserting it. The thermometer should be held in place for 2 minutes before reading it.

Species variations

Species	Normal	Critical point
Dog	100.9 - 101.7o F ; 38.3 - 38.7o C	105.0oF ; 41.0 o C
Cat	100.4 - 101.6o F ; 38.0 - 38.5o C
Rabbit	99.0 - 103.0o F ; 37.0 - 39.4o C
Hamster	98.0 - 101.0o F ; 36.2 - 37.5o C
Guinea Pig	99.0 - 103.0o F ; 37.2 - 39.5o C
Horse	100.5o F ; 38.0o C	102.0o F ; 38.8o C
Cattle	101.5o F ; 38.5o C	103.0o F ; 39.4o C
Sheep	102.5o F ; 39.2o C	104.0o F ; 40.0o C
Pig	102.0o F ; 38.8o C	103.5o F ; 39.7o C

• If the temperature exceeds the critical point for the species hyperthermia exists.
• Body temperature can vary by as much as 2^oF (1^oF) in many species during the day.

Last updated : October 2013