When we think of cruciate ligament tears (also called ACLs), it's usually in association with pro athletes or weekend warriors - but our dogs can suffer cranial cruciate ligament (CCL) injuries as well. In fact, it's the most common orthopedic problem that we see in back legs.
The cranial cruciate ligament is one of the ligaments that connects the thighbone to the shinbone where they meet at the knee (known as the stifle joint in dogs) and helps stabilize the joint. Basically, it keeps the knee fro sliding , allowing it to only rock.
What Causes CCL Disease?
When the CCL becomes injured - which can happen suddenly or over a long period - it's not only painful in the instant it happens, it also leads to painful arthritis if it's not repaired. Dogs typically suffer CCL tears/disease for three major reasons:
1) They are overweight.
2) They are out of condition and then are asked to perform athletic feats that are beyond their abilities
(weekend warrior syndrome).
3) They jump, twist, turn or land wrong.
CCL tears can result from long-term chronic degeneration. We don't know yet if there is a genetic component to CCL ruptures. Any breed or mix can suffer one, but this type of injury is most often seen in young Labrador Retrievers and Rottweilers (less than 4 years old), dogs older than 5 years, and young large-breed dogs. Other breeds that seem to have a disproportionate number of CCL injuries include Bernese Mountain Dogs, Mastiffs, German Shepherd Dogs, Golden Retrievers and Saint Bernards. Dogs who spontaneously injure one CCL are very likely to injure the other at a later point.
Signs of CCL Rupture
You may or may not see the actual injury occur. If you do, the first sign will likely be a loud yelp of pain from your dog.
The most obvious clue that your dog may have suffered a CCL injury is limping or reluctance to put weight on a rear leg. Your dog may hold his limb up or use the leg intermittently. Some dogs display what we call a lazy sit, holding the affected leg out to the side when sitting. You may notice that the stifle/knee joint is swollen or that it makes a clicking sound when your dog walks, which may indicate meniscal injury. In many instances, the injury may have been building up for some time. A CCL tear, or rupture, can be partial or complete.
Any time your dog appears to be lame, he should to be seen by a veterinarian. To diagnose the problem and rule out other causes of lameness, your veterinarian may manipulate the leg to check the stifle's range of motion,offer anti-inflammatory medication and prescribe rest. Radiographs (x-rays) or an MRI can also help to confirm a diagnosis, but are often done by a specialist.