Is that horse lame, or is he exhibiting neurologic signs such as ataxia (incoordination)? For some horse owners, answering this question can be difficult. Recent study results suggest, however, that owners aren't the only ones that find it challenging to evaluate a possibly ataxic horse: Researchers determined that equine health experts have difficulties agreeing on whether horses are ataxic and to what extent, especially when clinical signs are subtle. And this, the researchers noted, could lead to an “inaccurate or unreliable assessment of an underlying problem (which) might lead to misdiagnosis or inappropriate further testing and treatments.”

“Disagreement between vets is not due to the vet failing his/her duty or not being good enough, but partially because ataxia is a really difficult clinical sign, especially if it is subtle,” explained study author Emil Olsen, DVM, PhD, a large animal medicine resident at Cornell University, in Ithaca, New York.

Along with Richard Piercy, MA, VetMB, MS, PhD, Dipl. ACVIM, MRCVS, professor of comparative neuromuscular disease at England's Royal Veterinary College (RVC), Olsen studied horses that had been presented to the RVC for a neurologic assessment or with perceived ataxia, as well as a control group of horses with no clinical signs. Six large animal internal medicine and equine surgery specialists and residents evaluated the 25 horses during a live neurologic exam before re-evaluating the horses using videoed neurologic exams. Each horse underwent a full and identical neurologic gait assessment and the researchers scored the degree of ataxia on a five-point scale (with 0 being no ataxia and 5 being the most severe).

“We could see that there was wide disagreement on whether or not they believed a horse was ataxic, and particularly on the severity of the ataxia,” said Olsen. Horses with subtle gait abnormalities were especially problematic to assess, he noted