In addition, mild temperature elevations up to 103.5 can be seen in dogs that are excessively anxious or fractious. In recent years ear thermometers have been developed for veterinary use that are very similar to those commonly used by pediatricians. These devices have the advantage of being quicker and more comfortable for the patient. I have found them to be somewhat unreliable however, due to the large number of veterinary patients who have wax and other debris and exudate within their ear canals. One of the most important metabolic functions of any warm-blooded animal is maintenance of a normal body temperature, or thermoregulation.
Fever is defined as an elevation of body temperature above normal.
In dogs, fever is most often caused by infectious diseases. I see some dogs with very high fevers associated with diseases such as ehrlichiosis, parvoviral infection, distemper, and some fungal diseases. In addition, other disease processes can produce fever-producing substances called pyrogens that elevate body temperature. These are often inflammatory conditions such as immune mediated diseases. The extreme physical stress seen in dogs having severe seizures also can cause fever.