Cranial Cruciate Ligament Disease (CCL)
What is a CCL tear?
Cranial Cruciate Ligament Disease is the progressive failure of the cranial crucial ligament (CCL) in the canine knee or stifle, the middle joint on a dog’s rear limb. The CCL is one of the most important stabilizers in the stifle, connecting the femur and tibia in this complicated joint. Known as the anterior cruciate ligament (ACL) in humans, the CCL controls the forward thrust of the tibia or shin bone and the rotation of the stifle joint. Ruptures of this ligament can be partial or complete, causing degrees of rear limb instability, weakness, and pain.
Left untreated, CCL tears are a major cause of degenerative joint disease in the stifle. The American College of Veterinary Surgeons estimates that 40-60% of dogs who injure one CCL are likely to rupture the other at some point during their lifetime.
- CCL is known as the ACL in humans
- One of the most important stabilizers in the stifle (knee)
- 40-60% of dogs who tear one CCL will tear the other in the future
What causes a CCL tear?
Obesity and poor body condition are common contributing factors in CCL injuries. Additional weight and weak muscles put excessive strain on joints that, over time, will lead to degeneration of the ligament, reducing elasticity and strength, causing repeated micro tears and, eventually, rupture.
Repetitive actions like running, jumping, sudden stops, sharp turns, and weaving increase the likelihood of micro tears, especially in weekend warriors who may not be well conditioned for the activity such as Frisbee play or dog sports like agility.
Poor conformation or body structure can also put undue pressure on the ligament. Other orthopedic conditions, such as a luxating patella, also increase the likelihood of a rupture because the joint moves outside of its normal range of motion.
All breeds are susceptible to CCL tears. Dogs older than five and large breeds from one to two years old are common candidates. There is a higher instance of CrCLD in Labradors and Rottweilers younger than four years. Bernese Mountain Dogs, Staffordshire Terriers, Mastiffs, German Shepherd Dogs, Golden Retrievers, and St. Bernards also have a greater prevalence of CrCLD. The disease is more common in spayed females.
- Obesity is a common factor in CCL tears
- Repetitive actions increase the likelihood of a tear
- All breeds are susceptible to CCL tears
What are the symptoms of a CCL tear?
Initial
•If acute or sudden, sharp vocalization at the time of rupture.
•If degenerative, a progressive lameness
•Limping, toe-touching or refusing to bear weight on the limb
•Lazy sit where the injured limb is tucked under the body
•Swelling or heat in the knee
•Severe Pain
Intermediate
•Repeating cycle of distinct limping or lameness followed by period of self-limiting behavior, increased activity followed by re-injury and distinct lameness again
•Consistent mild to moderate limp
•Swelling
•Possible click during activity
•Atrophy of leg muscles
•Dog holds leg in partial bent position while standing
•Moderate Pain
Advanced
•Moderate to severe pain
•Moderate to severe limp or lameness
•Significant muscle atrophy
How is a CCL tear diagnosed?
Your veterinarian will likely start with a physical exam of your dog’s stifle, feeling for any excess movement in the joint, especially in the tibia. The cranial drawer test and the tibial compression test are common evaluation techniques to identify a ruptured CCL.
In these two tests, your veterinarian will engage the CCL by pulling the tibia forward (cranial drawer) or rotating the tibia when the limb is extended (tibial compression). If pain and excessive movement are present in either of these tests, there is likely a rupture of the CCL.
X-rays are often taken to confirm the diagnosis and rule out other causes, such as fractures and bone diseases. If your dog has pain in other joints, your veterinarian may recommend a joint fluid test called an arthrocentesis to look for toxins, microorganisms, and diseases of the immune system.
- Physical exam is the most common way to diagnose a CCL tear
- Cranial drawer test and tibial compression test are common physical assessment tools
- Xrays often taken to rule out other problems
Your dog has a CCL tear. How can we help?
We focus on improving the quality of life for dogs with a CCL tear and their pet parents. Our approach starts with assessing how your dog handles daily activities and identifying practical solutions for pain and mobility issues. We use activities like swimming, strength, balance, and flexibility exercises to build muscle, enhance joint mobility, and promote comfortable movement. Additionally, we recommend suitable mobility devices such as braces and harnesses to support both your dog and you, making daily routines smoother. We provide compassionate guidance to help you manage your dog's CCL tear effectively.
- Support quality of life during healing
- Use exercises to build muscle and mobility.
- Recommend mobility devices and offer guidance.