An equine pain face

TY - JOUR

T1 - An equine pain face

AU - Gleerup, Karina Charlotte Bech

AU - Forkman, Björn

AU - Lindegaard, Casper

AU - Andersen, Pia H.

PY - 2015/1/1

Y1 - 2015/1/1

N2 - Objective: The objective of this study was to investigate the existence of an equine pain face and to describe this in detail. Study design: Semi-randomized, controlled, crossover trial. Animals: Six adult horses. Methods: Pain was induced with two noxious stimuli, a tourniquet on the antebrachium and topical application of capsaicin. All horses participated in two control trials and received both noxious stimuli twice, once with and once without an observer present. During all sessions their pain state was scored. The horses were filmed and the close-up video recordings of the faces were analysed for alterations in behaviour and facial expressions. Still images from the trials were evaluated for the presence of each of the specific pain face features identified from the video analysis. Results: Both noxious challenges were effective in producing a pain response resulting in significantly increased pain scores. Alterations in facial expressions were observed in all horses during all noxious stimulations. The number of pain face features present on the still images from the noxious challenges were significantly higher than for the control trial (p = 0.0001). Facial expressions representative for control and pain trials were condensed into explanatory illustrations. During pain sessions with an observer present, the horses increased their contact-seeking behavior. Conclusions and clinical relevance: An equine pain face comprising 'low' and/or 'asymmetrical' ears, an angled appearance of the eyes, a withdrawn and/or tense stare, mediolaterally dilated nostrils and tension of the lips, chin and certain facial muscles can be recognized in horses during induced acute pain. This description of an equine pain face may be useful for improving tools for pain recognition in horses with mild to moderate pain.

AB - Objective: The objective of this study was to investigate the existence of an equine pain face and to describe this in detail. Study design: Semi-randomized, controlled, crossover trial. Animals: Six adult horses. Methods: Pain was induced with two noxious stimuli, a tourniquet on the antebrachium and topical application of capsaicin. All horses participated in two control trials and received both noxious stimuli twice, once with and once without an observer present. During all sessions their pain state was scored. The horses were filmed and the close-up video recordings of the faces were analysed for alterations in behaviour and facial expressions. Still images from the trials were evaluated for the presence of each of the specific pain face features identified from the video analysis. Results: Both noxious challenges were effective in producing a pain response resulting in significantly increased pain scores. Alterations in facial expressions were observed in all horses during all noxious stimulations. The number of pain face features present on the still images from the noxious challenges were significantly higher than for the control trial (p = 0.0001). Facial expressions representative for control and pain trials were condensed into explanatory illustrations. During pain sessions with an observer present, the horses increased their contact-seeking behavior. Conclusions and clinical relevance: An equine pain face comprising 'low' and/or 'asymmetrical' ears, an angled appearance of the eyes, a withdrawn and/or tense stare, mediolaterally dilated nostrils and tension of the lips, chin and certain facial muscles can be recognized in horses during induced acute pain. This description of an equine pain face may be useful for improving tools for pain recognition in horses with mild to moderate pain.

U2 - 10.1111/vaa.12212

DO - 10.1111/vaa.12212

M3 - Journal article

C2 - 25082060

SN - 1467-2987

VL - 42

SP - 103

EP - 114

JO - Veterinary Anaesthesia and Analgesia

JF - Veterinary Anaesthesia and Analgesia

IS - 1

ER -