Sunday, May 15, 2011

ASK THE EQUINIST: Stifle Problem?

In this new series, readers can write to me with their horse-related questions, and I will do my darndest to provide a solid answer, either from my own lifetime of experience or research I have conducted for veterinary-reviewed articles. If I don't have an answer, I will utilize my world-wide network of expert contacts to try to get one for you. To contact me, click on the link that says "THE EQUINIST" under where it says "About Me" on the lower left side of the main page, and you will find another link that says "email me".

Question: My horse seems to be short striding on his left hind, and he has worn that toe down more than the other one (he is not shod behind). I thought he must be sore on that foot or leg, but now he doesn't want to pick up his right lead canter, so I'm confused. Should I give him some time off and see if this goes away, or do I need to get the vet out? Does the worn toe mean it's a foot problem?

- Lisa R., TN

Answer: Sounds like your horse may have a stifle problem Lisa -- and don't feel bad, as many people are confused by situations like this with multiple symptoms that may appear to be contradictory. However, when a horse is sore on one hind leg, especially in the stifle or hock, it is quite common for them to feel pain when picking up the opposite lead canter, as the outside hind leg is the first to push off in the transition into the canter. In your horse's case, the short striding indicates that there is a problem in the left hind, but that is exactly the leg he needs to use to push off into the right lead canter.

The reason I suspect a stifle problem rather than a hock problem is the short striding and the worn toe. These are classic stifle symptoms, occurring because the horse feels discomfort when bringing the leg forward and upward. The discomfort will cause him to not want to bring the leg as far forward as he usually does (short stride), or to lift it as high as normal (causing the toe to drag and wear). When horses have a hock problem, they most often demonstrate a pain response during the pushing or loading phase of the stride, though they can have pain during flexion, as well.

While not as common as hock problems, stifle ailments are a frequent source of lameness in horses. They can result from repeated trauma, acute injury or an underlying condition. Symptoms may include:

· standing with the stifle rotated outwards

· locking or “hitching” of the joint

· reluctance to reach forward with the hind leg

· “stabbing” or toe-first landing with the foot on the affected hind leg

· short stride behind

· reluctance to pick up the canter when the affected leg is to the outside of a circle

· excessive wear on the toe

· reluctance to go downhill.

What I can't tell you, Lisa, is what kind of stifle problem your horse might have -- or if this even is a stifle problem for sure, and that's why I would suggest you get your vet out to take a look. If it is a stifle problem, it is likely to be one of the following:

  • Upward fixation of the patella (UFP), also called “locking” or “popping” stifles: Stifle joint locks completely or catches (partial UFP) when the horse tries to move the leg forward. Can occur in any horse but is most often seen in horses with straighter than average hock angles. A sudden lessening of activity in a fit horse may bring on this condition. Can often be successfully treated with specific exercises and/or counterirritant injections. Surgical options are available and quite successful. (See article on this blog about UFP)
  • Osteochondritis dissecans (OCD) lesions – a developmental disorder where the ends of the bones do not harden properly, possibly caused by excessive nutrient intake as a youngster. Most often seen in fast-growing, tall horses. Surgery is often necessary to correct this problem.
  • Meniscal damage – tears to this fibrocartilage can happen from sudden trauma. Difficult to diagnose. Surgery and rest has a success rate of about 50%.
  • Cruciate and anterior ligament damage: usually appears as an acute injury, but may be a result of repetitive strain. Prognosis and treatment varies with the severity of the injury.
  • Subchondral cysts: cyst-like lesions (usually not true cysts) that form just under the cartilage surface. Usually developmental in nature, though can be caused by trauma to the joint surface. Lameness may resolve on its own or require surgery. Younger horses with smaller lesions have better outcomes.
  • Sprains and bruising of the ligaments: can be difficult to pinpoint and diagnose. Will usually resolve with rest.
Yes, some of these conditions will resolve with rest alone, but if it is one that does require veterinary intervention, the sooner you catch it, the better. Left untreated, some of the conditions can become worse and harder to resolve. Best of luck with this, and let us know how it turns out!