In clinical practice, an important aspect of animal health status evaluation is the body temperature recording obtained using different methods. Within them, the non-contact and non-invasive infrared thermometer can provide an accurate estimation of body temperature improving the quality of care and medical decision. To evaluate the use of the monitoring of auricular temperature to improve the quality of care and medical decision. To evaluate the use of the monitoring of auricular temperature as indices of body temperature, as well as rectal temperature in eleven clinically healthy mixed bred cats, eleven Rottweiler dogs, and eleven Italian saddle horses temperature values were obtained by means of an infrared thermometer in the left and right ears and by means of a digital thermometer in the rectum. Two-way analysis of variance (ANOVA) indicated a statistically higher rectal temperature value than the temperature recorded in the left and right ears (P<0.001). In all species, no differences between the right and left ear were recorded (p>0.05). Cats and dogs showed a statistically higher auricular (p<0.001) and rectal (p<0.01) temperature compared to horses. No differences were observed between cats and dogs (p>0.05). Auricular and rectal temperature agreement was shown by the Bland-Altman test. Between the two methods, the average difference was 1.6 °C for cats, 1.4 °C for dogs, and 3.3 °C for horses. In dogs, rectal and auricular temperature showed a positive correlation (r=0.78). In conclusion, only in healthy dogs maintained in controlled conditions the monitoring of auricular temperature reflects the clinical practice gold standard of core body temperature measurement represented by rectal temperature. The lower value of about 1.5 °C must be taken into consideration when this technique is used.