The way they walk: gait abnormalities

Hunters require powerful hindquarters to do their job properly, yet some of these horses – particularly big, heavy hunters – can move their back legs in a very strange way at times.

These off hind limb actions are most noticeable as they move off, often quite briskly, after standing around getting cool. The observer can be left wondering whether they are lame or if they have a gait abnormality.

If they are still going strong at the end of the day’s hunting, such an abnormality may not actually be that important to the horse.

However, they may feel rather odd the first time you ride them, and this could be a work at a veterinary examination for purchase.

It is worth knowing which hind limb movement disorders are significant or serious. The following three are a common cause for concern:

Stringhalt

This is a hind limb gait abnormality with an exaggerated bending of one or both hindlegs, almost like a goose-stepping march. It is most obvious at a walk, particularly after a horse has been standing still in cold weather, such as after the meet), yet the horse will be normal at rest.

Signs are worse on turning and backing, and only one hindleg is usually affected.

• In the UK, the exact cause of stringhalt is unknown, but it is due to a motor nerve abnormality rather than a disorder of the musculoskeletal system. Some cases follow trauma to the hock or a tendon of the lower limb (the lateral digital extensor tendon).
• There is no magic treatment for the conventional stringhalt seen in the UK. Some cases are treated by surgery on the lateral digital extensor tendon, but, at best, the success rate is no more than 50%.
• If you have a suspected case, it is important to get your vet to confirm that it is stringhalt, as it can be confused with other conditions, particularly upward fixation of the patella.Locking stifle
  This is more properly called upward fixation of the patella. It is a mechanical lameness where a horse or pony is unable to unlock the stifle (or kneecap) from the extended position, so the horse hops forward with its leg stuck out behind. The toe may be dragged along the ground and the stifle and hock cannot be bent.It can look quite alarming and, at first glance, many people think that the limb is broken. Fortunately, the kneecap (or patella) does not lock, but catches with each stride.It may be more obvious when the horse is reversed or turned towards the affected side. When the stifle is not locked, the horse or pony will not be lame.
• Upward fixation of the patella occurs more commonly than stringhalt in ponies, but the two are easily confused. It is worse in horses in poor general condition or lacking fitness, and improves with increased work and better muscle tone.
• Upward fixation of the patella can often be easily treated. Many animals simply grow out of it, others respond well to a change in exercise pattern, while a few require surgical treatment.Shivering or shivers
  This is another mysterious and poorly understood disease of the nervous system. Farriers are probably most aware of the condition and know how common it actually is.This is because one of the biggest problems with horses which shiver is that they can be difficult to shoe. Such horses have a tendency to snatch the limb up, or for the limb to quiver when it is lifted. This in turn makes accurate fitting of shoes arduous.
• Apart from problems during shoeing, a horse who is a shiverer may to all intents and purposes appear normal. In many cases, it may not actually affect its performance.
• The signs associated with shivering may vary enormously from case to case and from day to day. The signs are inconsistent and can be easily undetectable on a one-off examination, which can make it very difficult to spot when assessing a horse before purchase
• The disease tends to start gradually, so that it may be obvious on one occasion and not there the next..
• Shivering is said to be progressive and may gradually become worse. But there is no way of predicting if or when they will get worse. Some horses spontaneously recover, while sometimes a rest can cure the problem.
• Traditionally, it is thought that shiverers are able to cope with flatwork, but their jumping ability is impaired. Some do cope without major difficulty, however.
• There is an unproven suspicion that the condition may be inherited. It seems to appear in certain breeding lines and a familial tendency is suspected. Mostly, it is seen on large, heavy adult horses, primarily draught horses, heavy hunters and warmbloods.Is it in the walk?
  Many horses with gait abnormalities remain undiagnosed, so is it just the way they walk?
• This article first appeared in H&H (31 October 2002)