Hind leg lameness is very common in dogs. The most common lameness that occurs with the hind legs is rupture of the cranial cruciate ligament (CCL). It is known as the anterior cruciate ligament or ACL in humans. If a dog is limping on his hind leg, most veterinarians assume it is a knee problem unless proven otherwise. The CCL can be ruptured by trauma or it can be a degenerative problem called cruciate disease. Certain breeds are subject to cruciate disease where the ligament is congenitally abnormal and not strong. This predisposes the dog to ligament rupture.

So how is a cruciate rupture diagnosed? Usually the veterinarian will perform a drawer test or a tibial thrust test. This involves manipulating the leg and checkin for abnormal motion. Sometimes this requires sedation as the dog may be very tense and will resist. Radiographs are also used to help in the diagnosis and to check for other problems.
If your dog has a cruciate rupture, he is probably bound for surgery although not always. Large breed dogs are more likely to require surgery, whereas smaller dogs may be okay with conservative treatment. Conservative treatment can be used if the ligament is not completely torn or if the dog is less than 10 lbs. Surgical repair can be done by an extracapsular repair where the knee is stabilized by a suture around the joint or a more invasive procedure called a TPLO ( tibial plateau leveling osteotomy) may be needed particularly in large dogs. Rehabilitation is crucial after this surgery and may consist of acupuncture or laser therapy, physio exercises and water therapy in an underwater treadmill. Conservative therapy with acupuncture, treadmill therapy, laser and supplements may be used in animals with incomplete cruciate tears. I have used Chinese herbs with great success for these dogs. If you have a large breed dog that may be in danger of cruciate disease ( labrador and golden retrievers) you may be able to strengthen the limbs and hips to help support the ligaments. This can be done by exercises and supplements. One of my favourite supplements to use with these dogs is Tendon Soup. I will post the recipe here if there is interest.