{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,9,3]],"date-time":"2026-09-03T17:05:04Z","timestamp":1788455104267,"version":"build-2803163510"},"reference-count":39,"publisher":"MDPI AG","issue":"8","license":[{"start":{"date-parts":[[2019,8,15]],"date-time":"2019-08-15T00:00:00Z","timestamp":1565827200000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Animals"],"abstract":"<jats:p>Physiological changes provide indices of stress responses, however, behavioural measures may be easier to determine. Spontaneous eye blink rate has potential as a non-invasive indicator of stress. Eyelid movements, along with heart rate (HR) and behaviour, from 33 horses were evaluated over four treatments: (1) control\u2014horse in its normal paddock environment; (2) feed restriction\u2014feed was withheld at regular feeding time; (3) separation\u2014horse was removed from visual contact with their paddock mates; and (4) startle test\u2014a ball was suddenly thrown on the ground in front of the horse. HR data was collected every five s throughout each three min test. Eyelid movements and behaviours were retrospectively determined from video recordings. A generalized linear mixed model (GLIMMIX) procedure with Sidak\u2019s multiple comparisons of least squares means demonstrated that both full blinks (16 \u00b1 12b vs. 15 \u00b1 15b vs. 13 \u00b1 11b vs. 26 \u00b1 20a full blinks\/3 min \u00b1 SEM; a,b differ p &lt; 0.006) and half blinks (34 \u00b1 15ab vs. 27 \u00b1 14bc vs. 25 \u00b1 13c vs. 42 \u00b1 22a half blinks\/3 min \u00b1 SEM; a,b,c differ p &lt; 0.0001) decreased during feed restriction, separation and the startle test compared to the control, respectively. Eyelid twitches occurred more frequently in feed restriction (p &lt; 0.0001) along with an increased HR (p &lt; 0.0001). This study demonstrates that spontaneous blink rate decreases while eyelid twitches increase when the horse experiences a stressful situation.<\/jats:p>","DOI":"10.3390\/ani9080562","type":"journal-article","created":{"date-parts":[[2019,8,15]],"date-time":"2019-08-15T11:11:00Z","timestamp":1565867460000},"page":"562","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":59,"title":["Eye Blink Rates and Eyelid Twitches as a Non-Invasive Measure of Stress in the Domestic Horse"],"prefix":"10.3390","volume":"9","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-9462-4150","authenticated-orcid":false,"given":"Katrina","family":"Merkies","sequence":"first","affiliation":[{"name":"Department of Animal Biosciences, University of Guelph, Guelph, ON N1G 2W1, Canada"},{"name":"Campbell Centre for the Study of Animal Welfare, University of Guelph, Guelph, ON N1G 2W1, Canada"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Chloe","family":"Ready","sequence":"additional","affiliation":[{"name":"Department of Animal Biosciences, University of Guelph, Guelph, ON N1G 2W1, Canada"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Leanne","family":"Farkas","sequence":"additional","affiliation":[{"name":"Department of Animal Biosciences, University of Guelph, Guelph, ON N1G 2W1, Canada"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Abigail","family":"Hodder","sequence":"additional","affiliation":[{"name":"Department of Animal Biosciences, University of Guelph, Guelph, ON N1G 2W1, Canada"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2019,8,15]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"33","DOI":"10.1016\/S0149-7634(97)00001-8","article-title":"Stress and emotionality: A multidimensional and genetic approach","volume":"22","author":"Ramos","year":"1998","journal-title":"Neurosci. 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