Quantitative sensory testing of the equine face.
Authors: Veres-Nyéki Kata O, Nyéki József, Bodó Gábor, Spadavecchia Claudia
Journal: Equine veterinary journal
Summary
# Editorial Summary: Quantitative Sensory Testing of the Equine Face Quantitative sensory testing is well-established in human medicine for assessing somatosensory function, yet equine baseline data remain sparse—a notable gap when evaluating conditions affecting facial sensation or pain perception. Veres-Nyéki and colleagues tested 34 healthy Warmblood horses across six facial locations, measuring tactile, mechanical nociceptive and thermal nociceptive thresholds using handheld devices to establish reference values and identify variables affecting sensitivity. Age emerged as a significant factor, with all three threshold types increasing progressively (tactile sensitivity declining by approximately 0.90 g per year, mechanical pain tolerance rising 0.25 N annually, and thermal tolerance increasing by 0.2°C yearly), whilst sex showed no meaningful influence on any measurement. Location of stimulation mattered for tactile and mechanical testing but not thermal assessment, and importantly, coat preparation proved unnecessary—shaving did not significantly alter results, simplifying clinical application. These findings provide practitioners with normative facial sensory data and practical guidance: handheld quantitative sensory testing is a reliable, low-preparation technique suitable for clinical use, offering objective assessment of facial sensation in horses presenting with suspected neuropathies, headshyness, or post-operative sensory disturbances.
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Practical Takeaways
- •Age-related increases in sensory thresholds suggest older horses may have reduced facial sensitivity to pain and touch—consider this when assessing facial pain or neuropathy
- •You don't need to clip or shave horses before performing quantitative sensory testing on the face, saving time and avoiding coat damage
- •Reference values from this study can now be used to identify abnormal sensory function in horses with suspected trigeminal nerve disease or facial injuries
Key Findings
- •All three sensory thresholds (tactile, mechanical nociceptive, thermal nociceptive) increased significantly with age in horses, with tactile threshold increasing by 0.90 g/year (P=0.001)
- •Sex had no significant effect on any of the three sensory thresholds tested (P>0.05 for all)
- •Stimulation site affected tactile and mechanical nociceptive thresholds but not thermal nociceptive threshold; optimal sites were nostril, temporomandibular joint, and supraorbital foramen respectively
- •Shaving or clipping had no significant effect on threshold measurements, indicating handheld quantitative sensory testing can reliably be performed on unclipped horses