Reliability of equine visual lameness classification

Oh dear, this report sheds a hard light on what has been known to be a problem with hind limb lameness evaluation: it can be difficult to localize to the correct lame leg. In this study it did not matter how experienced the person rating the lameness was. Surprisingly mild forelimb lameness were often identified as sound. There are now some pretty good video software products that make the evaluation more objective and I expect we will see more use made of these in the future.

What do you, as a horse owner do with this information? The article associated with this forum carefully explains how to identify the correct lame leg it would help to understand it. Be sure to critically analyze what your professional is telling you to see if it makes sense. Video taping the lameness can go a long way to help identify what exactly everyone is seeing. Lastly when things don’t seem to going as expected don’t hesitate to get a second opinion, best to a practice with video lameness software.
DrO

Vet Rec. 2019 Jan 12;184(2):63.
Reliability of equine visual lameness classification as a function of expertise, lameness severity and rater confidence.
Starke SD1, Oosterlinck M2.
Author information
Abstract
Visual equine lameness assessment is often unreliable, yet the full understanding of this issue is missing. Here, we investigate visual lameness assessment using near-realistic, three-dimensional horse animations presenting with 0-60 per cent movement asymmetry. Animations were scored at an equine veterinary seminar by attendees with various expertise levels. Results showed that years of experience and exposure to a low, medium or high case load had no significant effect on correct assessment of lame (P>0.149) or sound horses (P≥0.412), with the exception of a significant effect of case load exposure on forelimb lameness assessment at 60 per cent asymmetry (P=0.014). The correct classification of sound horses as sound was significantly (P<0.001) higher for forelimb (average 72 per cent correct) than for hindlimb lameness assessment (average 28 per cent correct): participants often saw hindlimb lameness where there was none. For subtle lameness, errors often resulted from not noticing forelimb lameness and from classifying the incorrect limb as lame for hindlimb lameness. Diagnostic accuracy was at or below chance level for some metrics. Rater confidence was not associated with performance. Visual gait assessment may overall be unlikely to reliably differentiate between sound and mildly lame horses irrespective of an assessor's background.