Daily Variation of Body Temperature: An Analysis of Influencing Physiological Conditions

The evaluation of thermoregulation in homeothermic animals is important for their health assessment. Body temperature is influenced by the circadian rhythm, which, through certain signals, is regulated by the suprachiasmatic nucleus. Temperature is collected by various methods; to reduce the invasiveness of rectal temperature sampling, considered the most accurate, infrared thermography has been used. The aim of the present review was to describe the circadian variability of average body temperature in several domestic animal species. In addition to variations due to the circadian rhythm, a number of conditions that can influence body temperature have also been studied. One example of this is exercise, which occurs in the case of domestic animals such as horses, dogs, and donkeys. In particular, it has been analysed in athletic horses, where, following intense exercise, the circadian rhythm of temperature is altered. The daily temperature variation during pregnancy and the neonatal period was also analysed. The circadian rhythm of temperature is influenced by the gestational period of sheep and goats, but this is affected differently depending on the type of species. The same is true for the neonatal period, in kids, lambs, and cattle, where the circadian rhythm is established at different times.