Use of Infrared Thermography to Assess Body Temperature as a Physiological Stress Indicator in Horses during Ridden and Lunging Sessions

SIMPLE SUMMARY: Equitation is based more on traditions than science. Current training methods might be efficient in the short term but lack scientific evidence that disproves any undesired effects they might have on the horse, both physical and emotional. This study aims to test easy-to-use technology (infrared thermography) for testing the fitness of dressage horses during ridden work, riding lessons and lunging and to find a relationship between the horse’s personality and its reaction to stress during exercise. The behavior during exercise was shown to reflect personality, sex and age, but thermographic readings exhibited no variation. Although the technology was not proven useful with dressage horses training in a familiar environment, its usage in combination with other tools is yet to be tested in such conditions. Despite personality affecting behavior, it did not have a relationship with the level of stress on the horse caused by exercising. Testing this technology can lead to the creation of efficient training programs, safeguarding horses from over- and underworking. ABSTRACT: Equitation is a cause of physiological stress in the equine athlete, and personality is a factor generally associated with the different responses of equines to stressors. This study explored ocular temperature, measured via infrared thermography, associated with personality and stress in horses submitted to dressage exercising in riding lessons, ridden training and lunging. Infrared thermograms of 16 horses were taken before and after sessions using an FLIR F4 camera (FLIR Systems AB, Sweden) to determine maximum eye surface IRT temperature (IRTmax), and total training time was registered (T). A novel-stimulus test was conducted for personality assessment, and the ridden behavior was scored (mRBS). The results showed that T was statistically different (p ˂ 0.001) between modalities, but no differences were found in any IRTmax tests. Statistical correlations were found between mRBS and personality groups, sex and age (all p < 0.001). Additionally—and with caution, given the sample—no association was found between mRBS and post-workout IRT readings and modality, or between pre-workout IRT readings and personality groups. We conclude that trained horses show little stress when working in a familiar environment and when the workout plan is submaximal. The personality test was adequate and positively correlated with ridden behavior.