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

http://www.thevetschoice.com/
http://www.crawforddogandcathospital.com/

What the H_LL is the ACL

OK, things got out of hand at work and I slipped back into an old pattern and I haven't posted for a while. I guess that when I decided to write about cruciate ligament injury in the dog, I found the topic so overwhelming that I just avoided the entire project. So, I'm going to divide it up into several smaller posts and the task will be easier for me to tackle. This post will deal with the ligament itself, and an explanation of some of the anatomy of the knee.

The knee is a pretty remarkable joint. The photo shows a model looking at the knee from the front. The joint, is a hinge, designed to flex and extend in one plain of motion similar to the way a door hinge opens and closes. It also has some very amazing shock absorbing principles, that allow us to run and jump. The joint runs into real problems when we ask it to do things it isn't designed to do like rotate, or hyper extend beyond it's normal range of motion.

There are extra articular structures (outside of the joint) that keep the knee stable. The muscles of the thigh that cross the joint and several collateral ligaments that do the same. You can see these collateral ligaments on the outside of the model.

Inside the knee, there are two cushions of cartilage, called the menisci. The medial meniscus on the inside and the lateral meniscus on the outside. They are labeled in the photo above. Finally, making a cross in the center of the knee are the two cruciate (cross) ligaments. The anterior (ACL) and caudal (CCL) cruciate ligaments. These guys keep the knee from sliding forward and backward. In fact the instability caused by injury to the ACL is called anterior drawer sign because when the muscles are relaxed you can actually pull the tibia (shin bone) forward like a drawer in a desk.

So now we all know where everything is. Next post I'll talk about what can happen to these structures. Then finally, we'll get around to explaining how they can be fixed.

Until next time, check us out at:

www.TheVetsChoice.com

www.CrawfordDogandCatHospital.com where you can search our library for free information