| dc.description.abstract | The Equine Utrecht University Scale for Facial Assessment of Pain (EQUUS-FAP) was developed for
box-rested horses and validated for acute colic pain, acute and post-operative head-related pain, pain after
orthopedic surgery and acute orthopedic trauma. Although it has been validated on live observations of boxrested
horses, it has not been validated on videos and photos of box-rested horses, though other studies
have done so with successful results for horses after castration or with acute laminitis. It has also not been
validated on ridden horses in locomotion, though previous studies have focused on pain expression in ridden
horses. EQUUS-FAP has also been used before on trotted horses with live observations, though this has not
yet been validated. In this study, the goal was to test the reliability and validity of the EQUUS-FAP scale
(modified for video and photo coding) in determining pain scores of trotting lame horses from videos and
photos, and to find out whether a correlation exists between pain face scores and an asymmetry index found
from Qualisys gait analysis. It was hypothesized that repeatability would be better for pain scoring from
photos than videos, and it was not expected there would be a greater difference between baseline and
induced lameness scores for photos than videos. It was also hypothesized that there would be a positive
correlation between pain face scores and the asymmetry index. Lameness was induced in eight horses using
two previously validated models (special modified shoe and LPS injection), and pain scores for each horse
were quantified after randomization of videos and photos during baseline and after induction of lameness by
two blinded observers, an equine veterinary specialist in anesthesia and a master’s student in Biology, both
of whom were trained to use the scale. Results from using the modified EQUUS-FAP pain scale for video and
photo scoring indicated acceptable reproducibility (intra- and inter-observer), though a significant increase in
pain-related expressions during guided trot after induction of lameness compared to baseline was not found;
consequently, no correlation was found between pain scores and Qualisys asymmetry scores. It was
concluded that this study does not support the clinical application of this pain scale using video and photo
coding for horses in locomotion with lameness. Several explanations were speculated, including effects of
other states such as stress, fatigue and fear on pain scores, the scale missing subtle elements of pain
expression for moving horses, and the quality of videos and photos not being adequate to detect more subtle
signs of pain. Future studies will have to confirm whether facial parameters could be used to assess pain
status in lame moving horses, or whether gait and body parameters, for example, should be included. | en_US |
