ACL injuries in Dogs
“Dr. Rannals, Fido has been limping on his back leg for over two weeks now. It happened all at once. We thought it was going to get better on it’s own, but it hasn’t.” This is a typical scenario for ACL injuries in dogs.
We frequently hear words very similar to this. In fact, rear limb lameness is a very common orthopedic problem in vet medicine. Sometimes it really is just a muscle strain or arthritis setting in. But often the problem is a torn ACL.
A Little Anatomy
A dog’s knee (stifle) is similar to a human’s, in that it has various ligaments that hold the knee together in proper alignment and allow it to function. In the middle of the knee are two large strong ligaments called the cruciate ligaments. The more forward ligament of the two is call the Anterior Cruciate Ligament (or cranial cruciate ligament). Just as in people, it can tear and leave the knee joint unstable and painful.
ACL injuries can occur in any breed, male or female, at any age. It does tend to be more common in middle age dogs. Onset is often sudden, where the pet starts holding that leg up and cannot bear weight on it. But sometimes the tearing occurs over a longer period of time, as the fibers of the ligament begin to pop. Those pets will often show a partial lameness. Fido may touch the foot to the ground but not bear full weight on it.
How we diagnose ACL injuries
Diagnosis of ACL injuries involves physical exam and nearly always sedation followed by knee manipulation and radiographs (x-rays). We looks for certain postures when the pet is sitting and feel for looseness of the knee when the dog is heavily sedated and the muscles are relaxed. Diagnosis is usually pretty straight forward.
How do we fix it?
There’s good news and bad news about ACL injuries in dogs. The bad news is that pills or shots, or other conservative treatments will not fix the torn ligament. It has a poor blood supply, so cells needed to heal it cannot reach the area very well. Don’t be mislead by claims of non invasive treatments that cure a torn ACL. If it’s torn, it’s torn. We do use medicine to help the pain and inflammation but that does not fix the problem. The good news is that there are surgical procedures that will restore function to the knee. In fact, many procedures have been used over the past several decades, and most are reasonably effective. Surgery in our hospital normally involves an overnight stay.
After surgery, restricted exercise for several weeks if important while the incisions and internal structures heal. Most dogs gradually gain strength in the knee and regain function to the leg.
Although an ACL tear is not an emergency, it is better not to wait too long on surgery. Over time, bone spurs and arthritic changes occur that can make the surgery less effective.
If you have more questions call the Rannals Small Animal Hospital at 903-839-7235.