Alternative methods to measure body temperature in dogs and cats

<title>Abstract</title> <p> Body temperature (BT) is an important indicator used during physical examination to assess the animal's health and disturbances to its body’s homeostasis. Digital rectal thermometry (DRT) is the current gold standard measurement method in small animals’ clinical veterinary medicine, surrogating for core body temperature. However, this method has multiple disadvantages, including inaccuracy due to local rectal variations, poor clinicians' safety, animals' discomfort, stress response, and relatively long measuring time. Auricular (tympanic membrane) infrared thermometry (AIRT) could be an attractive alternative, as it represents the hypothalamic temperature well. However, studies assessing its accuracy are scarce and absent in veterinary medicine. This study simultaneously assessed the BT of 100 hospitalized dogs and cats using DRT and AIRT to evaluate the agreement between them, analyzing their accuracy using the coefficient of variation. While DRT was more accurate than AIRT, both methods were reliable, well correlated (R ²  = 0.694), and in good agreement. Measurements by AIRT were mostly lower than by DRT, justifying using a correction factor of 0.5°C, which improved the agreement and correlation between the methods (R ²  = 0.833). Our findings suggest that AIRT was reliable and could substitute DRT when using the latter is impossible or inadvisable. </p>