Monday, May 11, 2009

Why is my dog lame?

So I was out running the Long Island Half Marathon with a couple of members of Team Crawford, our unofficial hospital running team, and had plenty of time to reflect on knees. I saw old knees, young knees, normal knees, knees with braces, ... you get the idea. Runners have plenty of knee issues. I'm at the age where many of my friends have had surgery on their knees for either meniscus damage or cruciate ligament injuries. So this problem is common in active older people as well as in dogs. The thing is, the nature of the injury is different in dogs and people, although the clinical signs (pain, swelling, lameness) are the same.

In people, injury to the ACL (anterior cruciate ligament) is usually a traumatic injury. You know, the tennis ball goes one direction and your knee goes the other. In dogs, ACL injury is usually a degenerative injury. The difference is subtle but important. In people, the ligament is often normal and is injured by the trauma. In dogs, the ligament is abnormal, and although the lameness is often proceeded by a perceived trauma, most often this ligament was going to pop sooner or later. The implication of this distinction is that the other ligament is often bad as well. So dogs with an injury to one ACL are at a much higher risk of tearing the ligament in the other knee.

Once the knee is destabilized by a torn ACL, other horrible things can happen in the joint. If you remember from the last post (It's OK, take a second to look back at the beautiful pirated photo of the knee model) there are other structures in the joint. That soft cushion of cartilage, the meniscus, is often torn at the time that the ACL goes. (see the illustration below) This causes more pain than the torn ligament sometimes. Knees with chronic partial tears can cause intermittent lameness. These knees tend to develop pretty bad arthritis over time.

Next post we'll talk about some options for treatment and possibly things we can do to minimize the undesirable effects of this condition. Until then, you might want to check this out to help your pet's joint health. Many runners I know use similar supplements designed for people, why not use one designed for dogs. I also know dogs that use Omega 3 fatty acids for arthritis. It is the major active ingredient in many joint diets, but in far too small a quantity. Here is a great way to get enough of a really good thing for you and your pets.

Keith Niesenbaum, VMD

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