Quantitative sensory testing of the equine face

• DOI: 10.1111/evj.13270
• Publication Date: 2020-04-19T01:43:45Z
• Authors: Kata O. Veres‐Nyéki; József Nyéki; Gábor Bodó; Claudia Spadavecchia
• Keywords: 0403 veterinary science; Hot Temperature; Reference Values; Sensory Thresholds; Animals; Pain; Reproducibility of Results; Horse Diseases; Horses; 04 agricultural and veterinary sciences

AbstractBackgroundQuantitative sensory testing methods are now standard in the evaluation of sensory function in man, while few normal equine values have been reported.ObjectivesThe aim of this experimental study was (a) to define the tactile sensory, mechanical nociceptive and thermal nociceptive thresholds of the equine face; (b) to assess the effect of age, sex, stimulation site and shaving; (c) to evaluate the reliability of the methods and (d) to provide reference facial quantitative sensory testing values.Study designMethod description.MethodsThirty‐four healthy Warmblood horses were used in the study. Six (tactile sensory threshold) and five (mechanical nociceptive and thermal nociceptive thresholds) areas of the left side of the face with clear anatomical landmarks were evaluated. Ten horses had two (mechanical nociceptive threshold) or three (tactile sensory and thermal nociceptive thresholds) of these areas shaved for another study. A linear Mixed model was used for data analysis.ResultsAll thresholds increased with age (tactile sensory threshold: by 0.90 g/y (CI = [0.12 g; 0.36 g]) P = .001; mechanical nociceptive threshold: by 0.25 N/y (CI = [0.13‐0.36 N]) P = .000; thermal nociceptive threshold: by 0.2°C/y (CI = [0.055‐0.361]) P = .008). Sex had no effect on thresholds (tactile sensory threshold: P = .1; mechanical nociceptive threshold: P = .09; thermal nociceptive threshold: P = .2). Stimulation site affected tactile sensory and mechanical nociceptive thresholds (P = .001 and P = .008), but not thermal nociceptive threshold (P = .9). Shaving had no significant effect on any of the thresholds (tactile sensory threshold: P = .06; mechanical nociceptive threshold: P = .08; thermal nociceptive threshold: P = .09).Main limitationsOnly the left side was investigated and measurements were obtained on a single occasion.ConclusionsHandheld quantitative sensory testing does not require shaving or clipping to provide reliable measurements. Stimulation over the nostril (tactile sensory threshold), temporomandibular joint (mechanical nociceptive threshold) and supraorbital foramen (thermal nociceptive threshold) resulted in the most consistent thresholds.