ACL Injuries in Dogs

Just like athletes can injure their knees and tear their ACL’s requiring surgery, so can your canine family member tear their ACL’s in their knees. In fact, ACL injuries in dogs is one of the more common musculoskeletal injuries we see in vet medicine.

ACL stands for Anterior Cruciate Ligament. (A newer term is actually CCL, for Cranial Cruciate Ligament.) It is one of two large ligaments inside the knee that criss cross each other and create stability in the knee joint, keeping the big bones from sliding back and forth against themselves. So when it tears or ruptures, the knee becomes unstable and bearing weight on it is uncomfortable or even painful. Usually, when a tear or partial tear occurs, the dog will not want to bear full weight on that rear limb. He may just touch it down for balance, or may even hold it up completely, especially when it first happens. Tucking that rear limb under himself to sit down may also be painful.

ACL tears can happen to any breed of dog at any age. But we tend to see them more in middle aged dogs, and slightly more in females. Although you would think about this being the result of extreme exercise like jumping to catch frisbees, ACL damage often occurs without any real background of unusual exercise. Often times owners just suddenly notice their pet is limping on a rear leg for no apparent reason.

Diagnosis of ACL injuries involves several aspects but generally will include heavy sedation and taking radiographs (X-rays) of the knees (called stifles in dogs) and usually also the hips. Any rear limb lameness that lasts more than several days is suspect for ACL injury. Fractures, hip dysplasia, and some other uncommon bone diseases may also show similar symptoms, and occasionally your dog may have just injured a muscle.

Repairing ACL tears ALWAYS will involve some sort of surgery. There are no magic medicines or injections that will cause the ligament to heal itself back together and reestablish joint stability. Although anti inflammatory treatments, like Rimadyl tablets, or cold laser therapy, may be useful in relieving inflammation and pain associated with the tear, they cannot fix the ligament.

There are several surgical techniques that are used to repair the knees and most are good at reestablishing a stable joint and use of that limb. Depending on the breed, size of dog, and anatomy of that particular knee structure, sometimes referral to an orthopedic surgeon is warranted for more specialized procedures (like TPLO). Restricted exercise for several weeks is always recommended post op until the knee heals well.

Most dogs that undergo surgery regain good use of the leg. However, it’s also very common to have arthritis in that knee develop over time, regardless of which technique is used. Various anti inflammatory meds can be used to treat this should it occur.

For more information or to set up an appointment at the Rannals Small Animal Hospital in Whitehouse, Tx, call 903-839-7235.