Knowledge Bank

Monitoring a horse's body temperature is essential for assessing its health and detecting early signs of illness. Body temperature in horses is commonly measured using a digital rectal thermometer (DRT). Although accurate, this method presents safety concerns for both horses and handlers. Non-contact infrared thermometers (NCIT) were widely used during the COVID-19 pandemic as a rapid and non-invasive way of measuring temperatures. The objective of this study was to evaluate the effectiveness and reliability of an NCIT in comparison with a DRT. The body temperature of ten adult Quarter Horses housed at The Ohio State University Equine Facility was measured weekly over five consecutive weeks (n=50). For each horse, body temperature was measured with a DRT and a NCIT in four different locations (under the tail, heart girth, forehead, and throat latch) at two distances from the body (3.8 and 7.6 cm). Pearson correlation coefficients were calculated using PROC CORR (SAS v. 9.4). The mean rectal temperature was 3.4 ± 17.3°C. In this study, the NCIT was not able to measure the body temperature at the horse’s forehead or throat latch at either distance. Mean differences recorded between the rectal body temperature and the NCIT under the tail 3.8 and 7.6 cm from the body were ± 1.0°C and ± 1.1°C, respectively. Mean differences recorded between the rectal body temperature and the NCIT at the heart girth were ± 2.1°C and ± 2.3°C, respectively. A weak, negative correlation was observed between the rectal temperatures and the temperatures recorded with the NCIT held under the horse’s tail (r = -0.22 and -0.21 at 3.8 and 7.6 cm from the body). However, temperatures recorded with the NCIT at the horse’s heart girth demonstrated a moderately positive correlation with rectal temperatures (p = 0.47 and 0.37 at 3.8 and 7.6 cm from the horse’s body). While NCIT are less invasive and potentially safer for the horses and handlers, they may not be as accurate as rectal thermometers for detecting body temperature.