Cause of foot pain baffles experts

SHERWOOD PARK, Alta. — Lameness is the most reported health concern in horses, but it is difficult to diagnose and treat.

“Diagnosing lameness is the most difficult things vets do,” said Dr Mike Scott of the University of Calgary’s faculty of veterinary medicine and a practitioner at Moore Equine in Calgary.

He favours a holistic approach when making a diagnosis rather than just looking at the horse’s feet or legs.

“Poor performance issues are often affected by their systems like their cardiovascular system or neck and back,” he said at the Alberta Horse Conference held in Sherwood Park Jan. 13-15.

“You really need to look at the whole horse.”

Vets need good observational skills while the horse walks and trots. A full history is required from the owner because the horse cannot describe where it hurts.

There are objective ways to assess problems, and technology is advancing to provide more precise results beyond the veterinary examination, which can be subjective.

Many horses may display abnormal gaits, so a flexion test may be done. This involves bending the hock and stifle and holding the leg in a fixed position. They are then released and encouraged to trot to see if lameness is present.

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“Probably a fair portion of horses that may be able to do their jobs well will have an abnormal flexion test result,” he said.

Ultrasound, X-rays, bone scans, CTs and MRIs may provide more objective gait analysis.

Digital radiography has advanced to the point where a veterinarian can do X-rays in the barn and look at images on the spot. However, X-rays can be expensive and do not show soft tissue well.

Portable ultrasound machines are available. This diagnostic tool can provide the best tool for looking at soft tissue but does not show fine detail.

Nuclear scintigraphy, also known as a bone scan, is a diagnostic tool used to localize bone fractures, joint inflammation, osteoarthritis and other injuries that may cause lameness. It is especially useful in areas that are difficult to reach on the neck, back and pelvis. It is very sensitive and can reveal multiple problems with the horse.

Bone scans are expensive, the images can look vague, but they can direct the vet to a trouble spot so treatment can be prescribed.

CT scans, more formally known as computed tomography, are possible. The horse is anesthetized before being placed in a doughnut shaped scanner. Standing systems are available, but they may not work well if the horse fidgets.

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MRIs, or magnetic resonance imaging, are available in some areas.

Washington State University was the first to try it and found good images were possible. Blurred images can happen as the horse moves, so new software is in development to provide better pictures.

It is restricted to hock, knee or lower extremities.

Standing MRIs are possible at the University of Saskatchewan’s Western College of Veterinary Medicine in Saskatoon, but they are costly and the operator requires skill and patience to get images from a horse over a couple hours.

An MRI study of the foot requires many sequences and images to show different perspectives of bones and soft tissue. The result could be 600 images that can be modelled into three-dimensional studies. Research has concluded that an MRI is the best diagnostic tool for foot pain, but it is expensive and results may be inconclusive.

For images of some of these technologies, visit www.hallmarq.net/equine/horse-owners.

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