Eye Temperature Measured with Infrared Thermography to Assess Stress Responses to Road Transport in Horses.
Authors: Aragona Francesca, Rizzo Maria, Arfuso Francesca, Acri Giuseppe, Fazio Francesco, Piccione Giuseppe, Giannetto Claudia
Journal: Animals : an open access journal from MDPI
Summary
# Editorial Summary: Eye Temperature as a Non-invasive Stress Marker in Travelling Horses Infrared thermography of the eye offers a practical, non-contact method for assessing acute stress responses in horses during road transport, a finding that could streamline on-site welfare monitoring for travelling athletes. Eight athletic horses were transported 100 km and 300 km on separate occasions, with eye temperature measured at three anatomical points (medial canthus, central cornea, lateral canthus) before, immediately after, and 60 minutes post-journey, alongside rectal temperature and serum cortisol. All three eye regions showed statistically significant temperature elevations following the 100 km journey that persisted at 60 minutes (p < 0.01), with eye temperature correlating positively to both rectal temperature and cortisol across multiple timepoints, suggesting these measurements track the same physiological stress response. The 300 km journey produced less pronounced eye temperature changes despite higher cortisol at recovery, indicating potential habituation effects in experienced travellers—a distinction that rectal temperature and cortisol alone might obscure. For practitioners managing transported horses, infrared thermography provides a quick, welfare-friendly alternative to blood sampling, enabling real-time assessment of stress levels at competitions, events, or during long journeys without restraint or sampling stress that would confound results.
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Practical Takeaways
- •Infrared thermography of eye temperature offers a quick, objective tool to monitor stress responses during road transport without restraint or handling
- •Eye temperature elevation correlates with established stress indicators (cortisol, rectal temperature), making it useful for welfare assessment during daily activities and travel
- •Consider implementing eye temperature monitoring as part of pre- and post-transport protocols to evaluate individual horse response to transport stress
Key Findings
- •Eye temperature increased significantly at all three regions of interest (medial canthus, central cornea, lateral canthus) following 100 km transport (p < 0.01)
- •Rectal temperature elevated at T2 and T3 after 100 km journey and at T2 after 300 km journey (p < 0.01)
- •Eye temperature positively correlated with both rectal temperature and serum cortisol concentration across multiple timepoints in both transport distances
- •Infrared thermography of eye temperature provides a practical, non-invasive method to assess physiological stress state during transport