Evaluation of facial expression in acute pain in cats

Holden, E; Calvo, G; Collins, M; Bell, A; Reid, J; Scott, E M; Nolan, Andrea M

doi:10.1111/jsap.12283

Authors

E Holden

G Calvo

M Collins

A Bell

J Reid

E M Scott

Prof Andrea Nolan A.Nolan@napier.ac.uk
Principal & Vice Chancellor

Abstract

OBJECTIVES
To describe the development of a facial expression tool differentiating pain-free cats from those in acute pain.
METHODS
Observers shown facial images from painful and pain-free cats were asked to identify if they were in pain or not. From facial images, anatomical landmarks were identified and distances between these were mapped. Selected distances underwent statistical analysis to identify features discriminating pain-free and painful cats. Additionally, thumbnail photographs were reviewed by two experts to identify discriminating facial features between the groups.
RESULTS
Observers (n?=?68) had difficulty in identifying pain-free from painful cats, with only 13% of observers being able to discriminate more than 80% of painful cats. Analysis of 78 facial landmarks and 80 distances identified six significant factors differentiating pain-free and painful faces including ear position and areas around the mouth/muzzle. Standardised mouth and ear distances when combined showed excellent discrimination properties, correctly differentiating pain-free and painful cats in 98% of cases. Expert review supported these findings and a cartoon-type picture scale was developed from thumbnail images.
CLINICAL SIGNIFICANCE
Initial investigation into facial features of painful and pain-free cats suggests potentially good discrimination properties of facial images. Further testing is required for development of a clinical tool

Citation

Holden, E., Calvo, G., Collins, M., Bell, A., Reid, J., Scott, E. M., & Nolan, A. M. (2014). Evaluation of facial expression in acute pain in cats. Journal of Small Animal Practice, 55, 615-621. https://doi.org/10.1111/jsap.12283

Journal Article Type	Article
Acceptance Date	Sep 15, 2014
Online Publication Date	Oct 30, 2014
Publication Date	2014-12
Deposit Date	Nov 25, 2014
Publicly Available Date	May 1, 2016
Journal	Journal of Small Animal Practice
Print ISSN	0022-4510
Electronic ISSN	1748-5827
Publisher	Wiley
Peer Reviewed	Peer Reviewed
Volume	55
Pages	615-621
DOI	https://doi.org/10.1111/jsap.12283
Keywords	Facial expression; Cats; facial features; pain assessment;
Public URL	http://researchrepository.napier.ac.uk/id/eprint/7355
Publisher URL	http://dx.doi.org/10.1111/jsap.12283