Although simple, measuring body temperature is a fundamental part of the physical exam in veterinary practice. New auricular thermometers have been used in children with good correlations to core temperature. In veterinary patients, such thermometers have been proposed, although studies that correlate its results with rectal temperature obtained by standard thermometers are still lacking. Therefore, this study was conceived to evaluate the clinical use of auricular thermometers in dogs, as well as to correlate these results with several measurements of rectal temperature. Twenty healthy normothermic dogs were enrolled in the study. Rectal temperature was measured with a mercury thermometer for 3 minutes (temp-3min), with a mercury thermometer until stabilization of the column (temp-stab), and with a digital thermometer (temp-dig). The auricular temperature was measured by two blind observers (temp-auric-1 and temp-auric-2). Pearson's correlation coefficient was calculated to determine the correlations between auricular temperature and rectal temperatures, as well as to determine the interobserver correlation (temp-auric-1 versus temp-auric-2). The mean temperatures for temp-stab, temp-3min, temp-dig, temp-auric-1 and temp-auric-2 (degrees Celsius) were 38.4±0.6; 38.8±0.5; 38.6±0.5; 38.7±0.6 and 38.7±0.4, respectively. The 95% confidence intervals were 38.1-38.7; 38.5-39.0; 38.4-38.9; 38.5-39.0 and 38.5-38.9, respectively. Significant agreement was determined to exist between temp-auric-1 and temp-3-min (r2=0.5646; P=0.0001), temp-auric and temp-stab (r2=0.5389; P=0.0002), temp-auric-1 and temp-dig (r2=0.5290; P=0.0003), and temp-auric-1 and temp-auric-2 (r2=0.5701; P=0.0001). Auricular temperature seems to be a reliable indicator of body temperature in dogs. Further studies are needed to investigate this apparatus in febrile and hypothermic animals.