Your loyal companion suddenly limps, and you worry about its health? Often, a cruciate ligament rupture is the cause of your dog’s mobility issues. Get all the essential information about “Cruciate Ligament Rupture in Dogs” in the following article!

Even though a cruciate ligament rupture is a serious matter, we can reassure you in advance: the diagnosis does not necessarily mean a lifelong limitation! With the help of our health tips, you can actively contribute to your pet’s recovery.

The Anatomy of the Dog’s Knee

The structure of the knee joints in dogs and humans is somewhat similar. In your dog, too, the knee is a hinge joint that connects the lower and upper legs, as well as the kneecap. The cruciate ligaments in dogs prevent the knee from twisting and ensure that your furry friend’s lower leg does not slip forward.

The Cruciate Ligament as one of the most important tendons in the knee

The cruciate ligaments, along with the collateral ligaments, stabilize the knee joint. Each knee joint has an outer and an inner cruciate ligament, actively participating in leg extension. The ligament gets its name because both bands cross in the center of the knee joint. If one of the cruciate ligaments tears, the stability and freedom of movement of the knee are significantly restricted.

Are you prepared for an emergency?

In humans, a cruciate ligament rupture usually occurs due to sports activities or sports accidents. In dogs, the situation is quite different. The cause of a cruciate ligament rupture in dogs primarily lies in your four-legged friend’s history. Therefore, different therapies and healing methods are applied to dogs.

What happens when a dog’s cruciate ligament tears?

One of the most common orthopedic injuries in dogs is the tear or partial tear of the anterior cruciate ligament. The posterior cruciate ligament is relatively rarely affected. Dogs stress the anterior cruciate ligament more than the posterior due to the given angle and high tensile forces. Most tears or partial tears happen in everyday, normal situations. For example, if your dog is chasing another animal or stumbles during a run, it can lead to cruciate ligament injuries. Older dogs, in particular, usually have weaker ligaments. In some cases, just stepping into a hole or getting caught on an irregularity can be enough.

Degenerative or Traumatic Rupture of the Cruciate Ligament

A rupture (tear) of the cruciate ligament can occur through two different pathways.

Traumatic Rupture:

On the one hand, an injury can occur as a result of an accident. In this case, it is referred to as trauma or traumatic rupture.

Degenerative Rupture:

If a cruciate ligament tear occurs due to prolonged wear and tear, it is called degenerative rupture in medical terms. Aging processes, misalignments, constant overloads can cause tears in your dog’s cruciate ligament that deepen over time. Thus, in the case of this type of cruciate ligament rupture, it is assumed that there was a pre-existing condition of the ligament. Overweight, excessive physical stress, or an unusual development of the shinbone favor degenerative cruciate ligament ruptures.

The difference between a cruciate ligament rupture in dogs and humans lies in the intensity of the tear. In dogs, the cruciate ligament usually tears fiber by fiber rather than completely.

Symptoms, Diagnosis, and Treatment

The Key Symptoms and Signs:

In most cases, a cruciate ligament rupture in your dog manifests as weight-bearing lameness. The lameness varies depending on the severity of the injury. In mild tears, your dog might limp for a few days and then return to normal walking. Such predispositions increase the risk of a sudden tear when your dog moves spontaneously and abruptly. Additionally, dogs tend to pull their hind leg up and carry it in a flexed position. They usually do not place the leg on the ground – if at all, only the tips of the toes touch the floor.

Furthermore, the following symptoms indicate a cruciate ligament rupture in dogs:

How is Cruciate Ligament Rupture Diagnosed in Dogs?

A cruciate ligament rupture is diagnosed with the so-called drawer test. The veterinarian uses this test to examine the mobility of the knee joint by pulling the lower leg towards the front limbs. If the lower leg can be pulled forward like a drawer compared to the thigh, it indicates a tear of the anterior cruciate ligament. Additionally, swelling is noticeable. This test is generally easier to perform on small dogs than on larger breeds. Large dogs have a higher muscle mass, which they tense during the test. This may cause the drawer test to yield negative results, even if your furry friend has a cruciate ligament rupture. To confirm the diagnosis, an additional X-ray is usually taken.

Diagnosis “Cruciate Ligament Rupture”: Surgery or No Surgery?

For small dogs, there may be the option of conservative therapy. Non-surgical therapy includes special feeding, joint rest, physiotherapy, and medication. The goal of this healing method is to enable pain-free loading of the knee joint. However, veterinarians usually do not recommend this approach. The reason is that with an untreated cruciate ligament, there is a risk of meniscus damage. In the worst case, both cruciate ligaments of your furry friend may tear over time due to extreme overloading of the healthy, remaining band. Untreated cruciate ligament ruptures can also lead to cartilage damage and arthritis. Surgery has the advantage that subsequent damage rarely occurs.

What Surgical Techniques are Available for a Torn Cruciate Ligament in Your Dog?

In cases of cruciate ligament ruptures, veterinarians choose from a variety of different surgical methods. On one hand, there are techniques that involve the use of the dog’s own connective tissue structures or artificial materials. In these surgeries, the cruciate ligament is replaced, and the joint capsule is tightened. On the other hand, there are methods that alter the biomechanics of the joint. Specifically, this means redirecting the forces acting on the knee joint.

The veterinarian decides individually on the medical approach for surgery, as each method has its advantages and disadvantages. The most common surgical techniques are referred to by the following names:

How do TPLO and TTA differ?

In a TPLO procedure, the veterinarian cuts the dog’s shinbone with a circular incision. Subsequently, special plates are placed at the respective locations, and the shinbone and plates are screwed into an altered position. The goal of this method is to prevent the biomechanical slippage of the lower leg, rendering the support function of the cruciate ligament unnecessary.

In a TTA, plates and a spacer are also screwed into the lower leg. Changes in the angle of the patellar ligament and the altered fusion of bone structures also prevent slippage of the lower leg. The advantage of both surgical techniques (compared to band replacement) is that the cruciate ligament cannot tear anymore because it has not been replaced. Therefore, after complete healing and physiotherapy, your dog may be able to participate in sports and protection work again.

After the Surgery: the Healing Process

Regardless of the surgical technique used, your furry friend should receive pain medication and, if necessary, cartilage-building supplements after the operation. The recovery time for TTA is approximately three months, while band replacement has a healing duration of about four months. Key measures during the healing process include consistent physiotherapy, regular weight checks, and gentle exercise. Learn more about how to assist your four-legged friend after the surgery here: Dog After Surgery.

Preventing a Cruciate Ligament Rupture in Dogs

If your dog currently has healthy cruciate ligaments or has undergone band replacement, you can take proactive measures to prevent a (recurrent) cruciate ligament rupture. Since overweight dogs put more strain on their joints and cruciate ligaments, ensure that your dog maintains a normal weight. Additionally, you can support your dog’s joints with dietary supplements, the appropriate choice of which will be advised by your veterinarian. Those planning to engage in high-performance sports with their dogs should consider the right age. High joint stress can lead to cruciate ligament ruptures in both puppies and seniors. However, an adult, normal-weight, and healthy dog will appreciate engaging in physical activity.

Checklist: What to Consider in the Case of a Cruciate Ligament Rupture in Your Dog