Most Common Knee Injuries in Dogs: Cruciate Ligament Disease Explained

Cruciate disease in dogs is typically a multifactorial degenerative condition. Predisposing factors include:  Genetics and breed  Medial patellar luxation  Obesity  Joint biomechanics  Desex status
Jan 7, 2025

Cruciate ligament disease is one of the most common causes of sudden hindlimb lameness in dogs. If your furry friend is limping or struggling to get around, it might be more than a simple strain. Here, we’ll explain what cruciate ligament disease is, what causes it, how it’s diagnosed, and the available treatment options to help your dog live a comfortable life.

What is Cruciate Ligament Disease?

The stifle (knee) is a crucial joint in your dog’s hindlimb. Inside the stifle, two ligaments—known as the cruciate ligaments—form an X shape, connecting the femur (thigh bone) to the tibia (shin bone). These ligaments work to stabilise the joint during movement.

In cruciate ligament disease, these ligaments weaken over time, leading to instability in the knee. This condition can progress to partial or complete ligament rupture, resulting in pain, lameness, and arthritis. If one cruciate ligament ruptures, the other leg is often affected within 12 months.

An anatomical diagram of a dog’s knee showing the patella (kneecap), femur (thigh bone), tibia (shin bone), fibula, and the cruciate ligaments forming an X within the joint, highlighting the key structures involved in stability and movement
An anatomical illustration of the dog's cranial cruciate ligament (CCL) within the knee joint, showing its position connecting the femur (thigh bone) to the tibia (shin bone) and demonstrating its role in stabilizing the joint during movement.

What Causes Cruciate Ligament Disease in Dogs?

Cruciate ligament disease is a degenerative condition caused by several factors, including:

  • Genetics and Breed: Certain breeds, such as Labradors, Rottweilers, and Newfoundlands, are more prone to cruciate disease.
  • Medial Patellar Luxation (MPL): Common in smaller breeds, this condition affects the kneecap’s stability, increasing the risk of cruciate rupture.
  • Obesity: Excess weight puts additional stress on your dog’s joints, contributing to ligament damage.
  • Joint Biomechanics: Abnormal joint structure or movement can lead to instability over time.
  • Desex Status: Studies suggest that desexed dogs may have a higher risk of developing cruciate disease.
Labrador. One of the most common type of dogs to get cruciate ligament disease.

Medial Patellar Luxation and Its Role

Medial patellar luxation (MPL) occurs when the kneecap (patella) moves in and out of its groove due to tendon laxity or a shallow patellar groove. This condition is common in smaller breeds with well-muscled hindlimbs and can lead to instability in the stifle joint, making a cruciate ligament rupture more likely.

If your dog is diagnosed with MPL, your veterinarian may recommend radiographs (x-rays) and, in some cases, surgical correction to prevent future complications.

How is Cruciate Ligament Disease Diagnosed?

Diagnosing cruciate ligament disease involves evaluating your dog’s stifle joint for signs of instability, including:

  • Drawer Sign or Tibial Thrust: This test checks for abnormal forward movement of the tibia relative to the femur. Sedation may be necessary if your dog is tense.
  • Swelling: Chronic cases often exhibit swelling on the sides of the knee (known as a “buttress”).
  • Radiographs (X-Rays): These can help rule out other causes of lameness, assess arthritis, and aid in surgical planning.

Treatment Options for Cruciate Ligament Disease

If left untreated, an unstable stifle joint will quickly develop degenerative joint disease (osteoarthritis), leading to chronic pain and reduced mobility. Treatment typically includes:

1. Weight Management

Maintaining a healthy weight is essential for reducing stress on your dog’s joints. If your pet is overweight, your vet can help design a weight-loss plan. You can also check out our blog on this topic HERE.

2. Surgical Intervention

Surgery is the most effective way to stabilise the joint and prevent further damage. Common surgical options include:

  • Tibial Plateau Levelling Osteotomy (TPLO): Alters the knee’s mechanics to eliminate instability.
  • Tibial Tuberosity Advancement (TTA): Adjusts the position of the patellar tendon to stabilise the joint.
  • De-Angelis Repair: Uses synthetic material to mimic ligament function (often recommended for smaller dogs).

3. Nutraceuticals and Supplements

These can help slow cartilage degeneration and provide pain relief:

  • Glucosamine: Supports cartilage repair.
  • Pentosan / Zydax / Synovan: Reduces joint inflammation and improves lubrication.

Your veterinarian may also recommend ongoing arthritis management. Check out our blog on osteoarthritis HERE for more tips on keeping your dog comfortable.

WEIGHT MANAGEMENT

Preventing Cruciate Ligament Disease in Dogs

While not all cases can be prevented, you can reduce your dog’s risk by:

  • Keeping them at a healthy weight.
  • Providing regular exercise to strengthen their muscles and maintain joint health.
  • Scheduling regular check-ups with your veterinarian to catch early signs of joint issues.

Final Thoughts

Cruciate ligament disease can be a challenging condition for both pets and their owners, but with timely intervention and proper care, many dogs can return to a happy, active life. If you’ve noticed your dog limping or showing signs of discomfort, don’t wait—contact The Village Vet today. Our team is here to provide expert care and help your furry friend stay on their paws.

Source

Dr Elle Burton-Bradley BAnVetBioSci (Hons I) DVM, Veterinarian, The Village Vet

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