As any sports fan knows all too well, ACL tears are a common injury among athletes. What you might not know, is that while there is no ACL in dogs, the CCL (cranial cruciate ligament) is essentially the same thing--with some key differences that make torn ACL style injuries even more common in dogs than they are in people!
What is the cranial cruciate ligament? The ACL in dogs
The anterior cruciate ligament (ACL) is a thin connective tissue in the middle of our (human) knees.
This connective tissue in dogs is called the cranial cruciate ligament (CCL) and it connects their bone below the knee (tibia) to their bone above the knee (femur). You can think of the CLL as a "dog ACL" and have the right idea!
Comparing the two, the most relevant distinction is that the CCL is always load-bearing because dogs never unbend their knees while standing. This "ACL in dogs" is thus subject to greater wear and tear than the average human's ACL and a dog's CCL naturally has to withhold greater stress.
What are the differences between ACL injuries in people and CCL injuries in dogs?
ACL tears occur due to an acute trauma stemming from a sudden movement such as a jump or change of direction, regular daily use should not contribute to a torn ACL. In dogs, CCL injuries tend to come on gradually, becoming progressively worse until a tear occurs.
Alright, I now understand what CCL injuries in dogs are, but how do I know if my dog has torn their CCL?
Most commonly a dog who has torn their CCL will demonstrate stiffness (typically most noticeable after rest that follows exercise), as well as difficulty rising, jumping, and/or walking without a limp.
Continued activity on a mildly injured leg will cause the injury to worsen and symptoms to become more pronounced.
Dogs suffering from a single torn CCL will typically begin favoring the non-injured leg, which commonly leads to the injury of a second knee. Approximately 60% of dogs with a single CCL injury will go on to injure the other knee soon afterward.
Ok, but can a dog live with a torn "dog ACL"?
Treating a dog's ACL or, more accurately, CCL injury with a knee brace is a non-surgical option that may help to stabilize the knee joint in some dogs. The support provided by a knee brace gives the ligament time to scar over and repair itself. Treating CCL injuries through the use of a knee brace may be successful for dogs when combined with restricted activity.
When should I consider "dog ACL" surgery?
You should ask your vet whether or not surgery is right for your canine companion. There are a number of different CLL repairing surgeries that vary in preferability based on dog breed, age, and size. Your veterinarian can recommend the best "ACL" surgery for your dog's specific needs.
Note: The advice provided in this post is intended for informational purposes and does not constitute medical advice regarding pets. For an accurate diagnosis of your pet's condition, please make an appointment with your vet.