Objective—To develop a visual analogue scale (VAS)
questionnaire that is repeatable and valid for use in
assessing pain and lameness in dogs.
Sample Population—48 client-owned dogs with
mild to moderate lameness.
Procedure—The dogs were from 3 studies conducted
during a 3-year period. Of the 48 dogs, 19 were
used in repeatability assessment, 48 were used in
principal component analysis, and 44 were used in
model selection procedures and validity testing. A
test-retest measure of repeatability was conducted
on dogs with a change of < 10% in vertical peak force.
A force platform was used as the criterion-referenced
standard for detecting lameness. Principal component
analysis was used to describe dimensionality of
the data. Repeatable questions were used as
explanatory variables in multiple regression models to
predict force plate measurements. Peak vertical, craniocaudal,
and associated impulses were the forces
used to quantify lameness. The regression models
were used to test the criterion validity of the questionnaire.
Results—19 of 39 questions were found to be
repeatable on the basis of a Spearman rank-correlation
cut point of > 0.6. Model selection procedures
resulted in 3 overlapping subsets of questions that
were considered valid representations of the forces
measured (vertical peak, vertical impulse, and propulsion
peak). Each reduced model fit the data as well as
the full model.
Conclusions and Clinical Relevance—The VAS
questionnaire was repeatable and valid for use in
assessing the degree of mild to moderate lameness
in dogs. (Am J Vet Res 2004;65:1634–1643)