Use of Infrared Thermography to Assess Body Temperature as a Physiological Stress Indicator in Horses during Ridden and Lunging Sessions.
Authors: Martins Joana Noronha, Silva Severiano R
Journal: Animals : an open access journal from MDPI
Summary
# Editorial Summary Infrared thermography (IRT) of the eye has been proposed as a non-invasive stress biomarker in horses, yet its reliability under typical training conditions remains unclear. Martins and Silva measured maximum ocular surface temperature using thermal imaging in 16 horses before and after three different exercise modalities—ridden lessons, ridden training, and lunging—whilst also assessing individual personality traits via novel-stimulus testing and recording ridden behaviour scores. Although training duration differed significantly between modalities, ocular temperature showed no measurable change post-exercise regardless of session type or pre-exercise baseline readings, nor did it correlate with personality classification, suggesting that trained horses under submaximal, familiar-environment workloads exhibit minimal detectable thermal stress responses. Ridden behaviour scores, however, demonstrated strong associations with personality type, age and sex, indicating these factors meaningfully influence how horses respond to handling and work. For practitioners, this implies that whilst ocular IRT may not be sensitive enough to detect stress during routine ridden work or lunging of accustomed horses, behavioural observation remains a reliable indicator of individual stress susceptibility and training tolerance.
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Practical Takeaways
- •Infrared thermography of the eye may not be a reliable standalone indicator of training stress in familiar, trained horses under submaximal workloads; consider multimodal stress assessment instead
- •Individual personality differences significantly influence how horses behave under saddle—personality testing can help predict behavioral responses during training and guide appropriate management strategies
- •Trained horses in familiar environments show minimal physiological stress markers even during varied training modalities, suggesting good habituation protocols reduce stress regardless of exercise type
Key Findings
- •Training time differed significantly between ridden, lunging, and riding lesson modalities (p ≤ 0.001), but no significant differences in maximum eye surface temperature were detected between pre- and post-workout measurements
- •Ridden behavior scores correlated significantly with personality groups, sex, and age (all p < 0.001), but showed no association with post-workout infrared thermography readings
- •Trained horses demonstrated minimal stress responses when working in familiar environments with submaximal exercise intensity, regardless of training modality
- •Novel-stimulus personality assessment was adequate and positively correlated with observed ridden behavior during training