Can a Dog Walk on a Torn ACL? A Vet‘s Comprehensive Guide

As a veterinarian and lifelong dog lover, one of the most common injuries I see in my canine patients is a torn cranial cruciate ligament (CCL), also known as the anterior cruciate ligament (ACL). This painful injury can be debilitating for dogs, often causing lameness, stiffness, and reduced mobility. Many worried dog owners come to me with questions like: Can my dog still walk on a torn ACL? What are the treatment options? Will my dog ever fully recover?

I understand how overwhelming it can be to navigate a CCL tear in your beloved furry family member. In this in-depth guide, I‘ll walk you through everything you need to know about this common canine injury, from anatomy and risk factors to treatment and recovery. My goal is to empower you with the knowledge and resources to help your dog regain their active, joyful life.

The Crucial Role of the ACL

First, let‘s dive into some canine anatomy to understand the important role of the ACL. The knee joint connects the femur (thigh bone) to the tibia (shin bone). The ACL is a strong ligament that runs diagonally across the knee joint, preventing the tibia from sliding forward relative to the femur. This maintains stability in the knee joint, especially during weight-bearing and high-impact activities.

Dogs actually have two cruciate ligaments in each knee – the cranial cruciate ligament in the front of the joint and the caudal cruciate ligament in the back. The CCL is more commonly injured than the caudal ligament.

When a dog tears their ACL, the joint becomes unstable, causing pain, inflammation, and often lameness in the affected leg. The bones rub together abnormally, which can lead to the development of arthritis over time.

How Common Are ACL Tears in Dogs?

ACL injuries are incredibly common in our canine companions. A 2021 study published in the journal Veterinary Surgery found that an estimated 5.6% of dogs will rupture their ACL at some point in their lifetime. However, this risk varies significantly by breed, with larger breeds being much more prone to ACL tears.

Breed	Incidence of ACL Tear
Rottweiler	22.2%
Neapolitan Mastiff	20.8%
Newfoundland	19.9%
Akita	18.9%
Saint Bernard	17.9%
Chesapeake Bay Retriever	15.4%
Labrador Retriever	10.9%
Golden Retriever	7.9%
Chihuahua	1.5%

Data from a 2018 study in Veterinary Medicine and Science

As you can see, large and giant breed dogs are at much greater risk for tearing their ACL compared to smaller breeds. This is likely due to a combination of factors including body weight, conformation, and activity level.

Can a Dog Still Walk on a Torn ACL?

Now, back to our original question: Can a dog still walk on a torn ACL? The answer is, it depends on the severity of the tear. Dogs can partially or completely tear their ACL. With a partial tear, the ligament is stretched or frayed but still somewhat intact. This can cause intermittent lameness, especially after activity.

A dog with a partially torn ACL may still put some weight on their leg and be able to walk around. However, you‘ll likely notice a limp and they may avoid putting their full weight on the affected leg. It‘s important to understand that walking on a partially torn ACL can cause the injury to worsen over time, potentially leading to a complete rupture.

With a complete ACL tear, the ligament is fully ruptured and the joint is no longer stable. This causes severe pain and typically leads to non-weight bearing lameness, meaning the dog will hold their leg up and refuse to put any weight on it.

In my experience, most dogs with a fully torn ACL will not be willing to walk more than a few steps at a time. The instability in the joint is very painful and they will guard the leg to avoid bearing weight.

So while it may be possible for a dog with an ACL injury to take a few steps, it‘s crucial to restrict their activity until you can have them evaluated by a veterinarian. Continuing to walk on an injured ACL will only worsen the joint damage and pain.

Signs Your Dog May Have a Torn ACL

Dogs are notoriously good at hiding pain, so it‘s not always obvious when they have injured their ACL. However, there are some key signs to watch for:

• Limping or lameness in the hind leg: This is the most obvious sign of an ACL injury. Your dog may hold their leg up or avoid putting weight on it.
• Sitting abnormally: Dogs with ACL tears often sit with their injured leg stuck out to the side rather than tucked under their body.
• Stiffness after rest: If your dog seems stiff or has difficulty rising after laying down, especially first thing in the morning, it could be a sign of knee pain.
• Clicking sound: Some dogs with ACL injuries will have a clicking noise coming from their knee when they walk. This is due to the bones rubbing together abnormally.
• Swelling: You may notice swelling or puffiness around your dog‘s knee joint, indicating inflammation.
• Reduced activity level: Dogs with painful ACL tears often become less active and no longer want to run, jump, or play like they used to.
• Muscle loss: In chronic cases, you may notice muscle atrophy or loss of muscle mass in the affected leg from disuse.

If you notice any of these signs in your dog, it‘s important to have them seen by a veterinarian right away. Prompt diagnosis and treatment can help prevent further joint damage and improve the long-term outcome.

Breeds at Higher Risk for ACL Tears

As we saw in the statistics above, certain breeds are much more prone to ACL injuries than others. Large and giant breed dogs are at the highest risk due in part to their heavier body weight placing more strain on their joints. Some of the breeds most commonly affected include:

• Rottweilers
• Newfoundlands
• Akitas
• Saint Bernards
• Chesapeake Bay Retrievers
• Labrador Retrievers
• Golden Retrievers

However, ACL tears can occur in any breed, even small dogs. In addition to genetics, factors like obesity, poor physical conditioning, and intense activity after periods of rest can increase a dog‘s chances of tearing their ACL.

Interestingly, research has shown that spayed and neutered dogs have a higher incidence of ACL tears compared to intact dogs. A 2020 study in PLOS One found that neutered males and spayed females had 2-3 times the risk of ACL tears compared to their intact counterparts. The exact reason for this is unknown but may relate to hormonal changes affecting ligament strength.

Congenital Conditions Affecting the ACL

Certain congenital conditions can also predispose dogs to ACL injuries by altering the biomechanics of the knee joint. The most common one we see is called medially luxating patellas.

Normally, the patella (kneecap) sits in a groove at the bottom of the femur. In dogs with luxating patellas, the groove is too shallow, allowing the kneecap to slip out of place, usually toward the inside of the leg.

When the patella luxates, it changes the forces on the ACL, making it more likely to tear over time. It‘s not uncommon for us to see dogs, especially small breed dogs, with the combination of a luxating patella and a torn ACL in the same knee.

Diagnosing an ACL Tear

If you suspect your dog has torn their ACL, the first step is to visit your veterinarian for an evaluation. During the appointment, your vet will take a thorough history, asking about your dog‘s activity level, any known trauma, and the progression of symptoms.

Next, they will perform a complete orthopedic exam, palpating your dog‘s knee joint and assessing its stability. Two tests commonly used to diagnose ACL tears are the cranial drawer test and the tibial compression test.

For the cranial drawer test, your vet will hold the femur stationary with one hand while manipulating the tibia with the other hand. If the tibia can be shifted forward like a drawer sliding open, it indicates the ACL is no longer intact. The tibial compression test involves flexing the hock joint while stabilizing the femur. If the tibia shifts forward, it also suggests an ACL tear.

In some cases, sedation may be needed to get a definitive diagnosis, especially if your dog is very painful. X-rays are also often recommended to assess the degree of arthritis in the joint and to help guide the treatment plan.

For more subtle partial tears, advanced imaging like MRI or arthroscopy (inserting a small camera into the joint) may be needed to directly visualize the ligament.

Treatment Options for ACL Tears

The best treatment for your dog‘s torn ACL will depend on several factors including their size, age, activity level, and the severity of the injury. The two main categories of treatment are conservative management and surgery.

Conservative Management

For dogs with partial ACL tears, especially in small breed dogs, conservative management may be attempted first. This typically involves a combination of:

• Strict rest: Your dog will need to be confined to a small space like a crate or playpen for 6-8 weeks to allow the ACL to heal. Leash walks should be kept short and low impact.
• Pain control: Your vet will prescribe anti-inflammatory pain medications to reduce inflammation and discomfort in the joint.
• Physical therapy: Controlled exercises and modalities like cold laser, underwater treadmill, and passive range of motion can help improve function in the leg and prevent muscle atrophy during the rest period.
• Weight management: If your dog is overweight, your vet will likely recommend a weight loss plan to reduce stress on the joint.

The goal of conservative therapy is to allow scar tissue to form over the torn ligament, stabilizing the joint. However, this approach is typically only successful in about 20% of cases. Most dogs will either re-tear the ligament or develop progressive arthritis due to the instability.

Surgical Treatment

For most medium to large breed dogs and those with complete ACL tears, surgery is recommended to stabilize the joint and prevent further injury. There are several surgical techniques that can be used depending on your dog‘s size and conformation.

• Extracapsular repair: This is often the preferred technique for small to medium breed dogs. The surgeon places a strong suture outside the joint capsule to mimic the function of the ACL and prevent the tibia from sliding forward.
• Tibial plateau leveling osteotomy (TPLO): With this procedure, the surgeon makes a curved cut in the tibia and rotates the tibial plateau to change the biomechanics of the joint. This eliminates the need for the ACL to stabilize the joint. TPLO is often recommended for large breed dogs and those with steep tibial plateaus.
• Tibial tuberosity advancement (TTA): Similar to TPLO, TTA involves making a cut in the front of the tibia and advancing the tibial tuberosity forward to change the forces on the joint. This is also a good option for larger dogs.

Your veterinarian or veterinary surgeon can recommend the best procedure for your dog based on their individual anatomy and lifestyle.

It‘s important to know that even with surgery, your dog will still require a lengthy recovery period and rehabilitation to regain full function of their leg. Most dogs take 3-4 months to recover fully from ACL surgery.

Recovery and Long-Term Management

Recovering from an ACL tear is a marathon, not a sprint. Whether your dog has surgery or is being managed conservatively, they will need a gradual return to activity to allow the joint to heal and adjust to the new biomechanics.

Your vet will give you detailed instructions on how to care for your dog during the recovery period, but here‘s a general timeline of what to expect:

• First 2 weeks: Your dog should be strictly rested with only short leash walks for bathroom breaks. Ice the incision site for 10 minutes several times a day to reduce swelling.
• Weeks 2-4: You can start taking your dog on slightly longer leash walks, gradually increasing the time and distance. Continue icing the knee as needed. Passive range of motion exercises can help improve mobility.
• Weeks 4-8: Introduce more active exercises like sit-to-stands, walking over cavaletti poles, and balancing on a wobble board. Underwater treadmill therapy is often started during this phase.
• Weeks 8-16: As your dog regains strength and mobility, you can start reintroducing off-leash activity in a controlled environment. Continue with physical therapy exercises to build muscle and endurance.

It‘s crucial to follow your vet‘s recommendations for activity restriction to avoid setbacks in healing. Too much activity too soon can cause pain, inflammation, and even re-injury.

Even after your dog has fully recovered, it‘s important to understand that they are at higher risk for tearing the ACL in their other knee. Studies have shown that 40-60% of dogs that tear one ACL will go on to injure the opposite side within 1-2 years.

To help prevent this, it‘s important to keep your dog at a lean body weight, provide regular low-impact exercise, and support their joint health with supplements like glucosamine and omega-3 fatty acids. Your vet may also recommend starting your dog on a joint supplement preventively if they are at high risk for ACL tears.

The Future of ACL Treatment in Dogs

While surgery remains the mainstay of treatment for most dogs with ACL tears, regenerative medicine therapies are an exciting area of research that may offer new options in the future.

Platelet-rich plasma (PRP) and stem cell therapy are two regenerative therapies that have shown promise in early studies for treating ACL injuries in dogs. PRP involves taking a sample of the dog‘s own blood, concentrating the platelets, and injecting them back into the injured joint. The growth factors in the platelets can help reduce inflammation and promote healing.

Stem cell therapy uses the dog‘s own stem cells, usually derived from fat tissue, to promote regeneration of damaged ligament tissue. While more research is needed, these therapies may offer a less invasive alternative to traditional ACL surgery in the future.

A Message of Hope

As a veterinarian, I know how devastating it can be to receive a diagnosis of a torn ACL in your beloved dog. But I want to offer a message of hope. With proper treatment and rehabilitation, the vast majority of dogs recover well and go on to live active, happy lives.

I‘ve seen countless patients in my practice bounce back from ACL injuries and regain their zest for life. From the tiny Yorkshire Terrier who underwent extracapsular repair surgery to the 150-pound Mastiff who had TPLO, I‘ve witnessed the resilience and strength of dogs time and time again.

The key is to seek prompt veterinary care, follow your vet‘s recommendations closely, and stay committed to your dog‘s recovery plan. It may be a long road, but it‘s so worth it to see your furry friend running and playing again without pain.

If you‘re currently navigating an ACL tear with your own dog, know that you‘re not alone. Lean on your veterinary team for support and don‘t hesitate to reach out with any questions or concerns along the way. Together, we‘ll help your dog get back to living their best life.