Cranial Cruciate Ligament Injuries in Dogs
Written by Small Door's medical experts
The cranial cruciate ligament (CCL) is a ligament in dogs’ knees that helps to stabilize the joint. Injuries to the CCL cause instability in the joint, leading to lameness, pain, and arthritis. Depending on the severity of the injury, treatment options may include surgery and/or a variety of lifestyle modifications, pain medications and physical therapy.
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A cranial cruciate ligament injury refers to a torn ligament in the knee, which causes painful joint instability and makes it difficult for your dog to move normally.
In humans, the cranial cruciate ligament is called the anterior cruciate ligament (ACL). You’ve probably heard of ACL tears in people. While there are similarities between the human and canine ligament tears, there are also some important differences.
Most ACL tears in humans are the result of a sudden (acute) injury. Dogs, however, can experience different degrees of rupture, which is why the condition is often referred to as cranial cruciate ligament disease, rather than tear. Tears can be partial or complete, and may develop and progress over time. This makes it doubly important to be aware of any symptoms, as with intervention, progression may be slowed.
Another key difference from ACL tears in humans is that pets with CCL disease in one knee are more likely to develop it in the other knee.
Symptoms of cranial cruciate ligament injuries in dogs affect their gait and comfort. These signs include:
Decreased activity levels
Difficulty rising after sitting
Unwillingness to play
Decreased range of motion in the knee
Muscle atrophy (decreased muscle mass in the affected leg)
Swelling on the shin bone
Popping sound (which could indicate a meniscus tear)
Dogs may develop cranial cruciate ligament disease for several different reasons, including genetic predisposition and injury. Unlike people, most cranial cruciate ligament injuries in dogs are not acute, and instead tear over time.
Common causes include:
Dogs with poor body conditions, especially overweight dogs, are more likely to develop a cranial cruciate ligament tear or partial tear, as weight puts increased stress on the joints and ligaments – especially if your pet is also out of shape.
In most cases, cranial cruciate ligament injuries result from a combination of the above factors.
Certain breeds of dogs are predisposed to cranial cruciate ligament injuries, including:
Chesapeake Bay Retrievers
Your veterinarian will begin with a physical exam and gait observation. They will carefully manipulate your pet’s joints and will also look for signs of muscle atrophy and swelling.If the gait observation and physical exam lead your veterinarian to suspect a cranial cruciate ligament injury, they will then suggest radiographs (x-rays) to confirm the diagnosis. Diagnostic imaging like radiographs can confirm any joint effusions and arthritis, help them make measurements to plan for surgery, and will also help rule out other causes of lameness, such as fractures or dislocations.
Complete cranial cruciate ligament tears are comparatively easy to diagnose, whereas partial tears tend to require further investigation.
The best treatment option for your pet will depend on the degree of the tear and your pet’s condition. Factors like size, age, activity levels, conformation, and the degree of instability in the knee joint all play a role. Surgical treatment is the only permanent way to control the instability of the knee. However, alternatives to surgery may be necessary depending on budget and your pet’s overall age and condition.
There are several surgical approaches veterinary surgeons take to treat cranial cruciate ligament injuries. The ligament itself cannot be repaired, as it lacks the ability to heal. Your veterinarian may opt for:
Osteotomy-based technique, like a tibia plateau leveling osteotomy (TPLO) or a tibial tuberosity advancement (TTA)
Suture-based techniques, such as extra-capsular suture stabilization or the Tightrope
Repair without surgery is usually not possible. However, non-surgical options can help slow progression and keep your dog comfortable. Pain medications, joint supplements, rehab, exercise modification, and knee braces may be moderately effective. Restricting exercise is the most important component of non-surgical approaches, as the instability of the joint and the source of pain remains.
Limited research exists to support rehab and braces as effective alternatives to surgery, but they may help aid in recovery.
Is there a cure for cranial cruciate ligament injuries in dogs?
There is no cure for cranial cruciate ligament tears in the strict sense; torn ligaments cannot repair themselves, and the damage to the ligament is therefore permanent. However, surgical treatment can stabilize the knee joint in other ways, effectively “curing” the condition. Arthritis may remain, depending on the progression of disease.
Are Cranial Cruciate Ligament Injuries Contagious For Humans or Other Pets?
There are no known direct contagious causes for cranial cruciate ligament disease. However, in cases where genetics and poor conformation play a role, owners should not breed from their dog.
What is the cost for treating cranial cruciate ligament injuries in dogs?
The cost for treating cranial cruciate ligament injuries depends largely on whether or not you pursue surgical treatment. Surgical options like TPLOs can cost thousands of dollars, and it is worth noting that 40-60% of dogs with cranial cruciate ligament injuries in one knee will most likely develop it in the other. However, surgery is usually the best choice, especially for young and otherwise healthy dogs. Plan for the cost of surgery itself, along with follow-up appointments and diagnostics, pain medications, and potential surgical complications.
The success rate of surgery depends largely on post-surgical care. Activity restriction is crucial, as excessive or uncontrolled activity can cause the surgery to fail. Your veterinarian will give you complete instructions on postoperative care, but they will most likely include strict exercise restriction and rest. Physical therapy can also help speed recovery. Rehab may include controlled leash walks, balance exercises, and range of motion exercises.
Statistics show significant improvement in 85-90% of cases with surgical intervention. While arthritis may still progress, it is usually slower in cases with surgical management. Your veterinarian may also suggest weight loss if your pet is not at their ideal weight, as this will take stress off their joints. Sometimes weight loss will be required prior to surgery, to improve the likelihood of a successful recovery.
Cranial cruciate ligament injuries can not always be prevented. However, if your dog is a breed with a known predisposition or if your dog has poor conformation, there are steps you can take to reduce the risk or slow the progression of cranial cruciate ligament injuries.
The most important thing you can do is make sure your dog is at an ideal weight and body condition. This is done with the help of your veterinarian, and is typically through controlled diet and exercise. A good diet and regular exercise regimen will also improve your pet’s overall health and quality of life.
Is there a vaccine for cranial cruciate ligament injuries?
No, there is no vaccine for cranial cruciate ligament injuries.
Cranial cruciate ligament injuries are serious but treatable conditions that cause lameness, pain, and reduced motion in dogs. Luckily, there are surgical and non-surgical options available to treat cranial cruciate ligament tears. The prognosis for dogs with cranial cruciate ligament injuries is typically very good with surgery.