The objective of this experiment was to determine the relationship between rectal temperature and infrared temperature measured on the inner eye, center- and ear base of sows undergoing anesthesia. A total of six sows were used. Sows were anaesthetized using a combination of xylazine, tiletamine HCl and ketamine. Thermal images at the inner ear, ear center and ear base were taken at 10 minute intervals starting ten minutes’ post-anesthetic induction until the sow was able to stand or reached 91.7◦ F body temperature. Rectal temperatures were measured using a digital thermometer. Rectal temperature Pearson correlations were determined among the inner eye, center and ear base with a significance level set at P ≤ 0.05. Percent variation accounted for by these locations was calculated as the correlation coefficient (r) raised to the second power and multiplied by 100 (r2 x 100). There was a positive correlation between rectal and inner eye, ear center and base (P ≤ 0.03). The lowest correlation was between the ear base and accounted for 9% of the sows’ rectal temperature variation. The correlation was the greatest for the inner eye and accounted for 38% of the sow’s rectal temperature variation. In conclusion, thermal images of the inner eye provided an effective and less invasive approach to rectal temperature for sows undergoing anesthesia.