How To Tell If Dog Tore Acl: Symptoms & What To Do

A dog tears its ACL, also known as the cranial cruciate ligament (CCL), when that ligament in the knee (stifle) ruptures or tears. Immediate signs of a dog ACL tear often include sudden lameness or dog limping after activity.

A torn ACL is a very common injury in dogs, especially active or overweight ones. It causes instability in the knee joint. This instability leads to pain and further damage if not treated. Knowing the signs is key to getting your pet fast help. This guide will help you spot the dog ACL tear symptoms and know the next steps to take for your beloved companion.

Deciphering the Symptoms of a Dog ACL Tear

Recognizing a dog rear leg injury can sometimes be tricky. Dogs are masters at hiding pain. However, a torn ACL usually causes noticeable changes in how your dog moves. These canine CCL rupture signs can show up suddenly or slowly over time.

Sudden Onset Lameness

Often, the injury happens during play or exercise. You might see your dog suddenly stop using one back leg.

They might put no weight on the leg at all (non-weight bearing).
Sometimes, they only put a little weight on it.
This sudden halt in normal walking is a major clue for a dog injured CCL.

Subtle Lameness and Favoring a Leg

In other cases, the tear might be partial, or the injury might be older. You may notice less dramatic changes first. This is when you might notice your dog favors back leg movement.

Intermittent Limping: The limp comes and goes. It might be worse after rest.
Stiffness: Your dog seems stiff, especially after waking up or sitting for a long time.
Difficulty Rising: It takes longer for your dog to get up from a lying position.
Hesitation on Stairs: They might refuse to use stairs or jump onto furniture. They might try to use three legs instead of four.

Changes in Gait and Movement

The way your dog walks will change due to the instability in the knee joint. This dog hind leg lameness is central to diagnosing the issue.

“Sciamming” or Hopping: Instead of a normal walk, your dog might hop or skip slightly on the injured leg. They might keep the leg slightly bent.
Foot Drags: They might drag the top of their foot (the toes) when walking. This shows poor control over the limb.
Decreased Activity: Your dog simply does less. They might stop wanting to play fetch or go on long walks.

Physical Signs of Pain and Discomfort

While watching your dog move is important, feeling the leg can also reveal issues. Be very gentle when checking your dog, especially if they are already painful.

Swelling: The knee area might look puffy or swollen compared to the other leg.
Tenderness: Your dog might pull away or whine if you touch or press near the knee joint.
Muscle Loss (Atrophy): Over time, if the injury is ignored, the thigh muscles on the injured side will start to shrink. This is because the dog avoids using that leg. You can often see this by comparing the muscle size of the two rear legs.

Fathoming the Causes of Canine CCL Rupture

Why do dogs tear their ACLs? The dog CCL rupture signs are the effect, but the cause is important too. It is rarely a single, dramatic event, especially in smaller dogs.

Predisposing Factors

Several factors increase the risk of this dog rear leg injury.

Genetics and Breed: Certain breeds are more prone to ACL tears. These include Labrador Retrievers, Rottweilers, Newfoundlands, and Boxers.
Weight: Obesity places far too much stress on the knee joints. Extra weight is a huge risk factor for any age of dog.
Age and Degeneration: Like humans, a dog’s ACL can weaken over time. Small tears lead to bigger ones, eventually resulting in a full rupture.
Activity Level: Sudden, awkward twisting motions during intense play or sports can cause an acute tear.

Acute vs. Chronic Tears

It helps to know how the tear happened.

Acute Tear: This happens all at once. Maybe your dog jumped off the couch awkwardly or planted their foot wrong while running. You see immediate, severe lameness.
Chronic Tear: This is more common, especially in middle-aged or senior dogs. The ligament slowly frays due to wear and tear. The dog shows mild, inconsistent lameness that gets worse over months. Often, a small tear eventually leads to a complete rupture.

Immediate Steps When You Spot Dog ACL Tear Symptoms

If you suspect your dog has a dog injured CCL, what should you do right away? The first goal is to prevent further injury and manage pain until you can see a professional.

Restrict Activity Immediately

The most crucial step is stopping all movement that puts weight on the leg.

Leash Only: Do not let your dog roam freely. Keep them on a short leash for bathroom breaks only.
No Stairs or Jumping: Carry your dog up and down stairs if possible. Block access to furniture or beds.
Crate Rest: Confine your dog to a crate or small, secure room where they cannot run or jump. This limits stress on the knee.

Assess the Injury Gently

A quick, gentle check might give you more information, but stop immediately if your dog shows severe pain.

Look for Swelling: Compare both rear legs visually.
Observe the Foot Placement: Is the paw turned outward? Does the leg look bent strangely?

Contact Your Veterinarian

Do not wait to schedule a vet visit for dog knee injury. Even if the lameness seems mild, an unstable knee joint requires professional attention.

Call your primary vet or an emergency clinic immediately.
Describe exactly what you saw. Did the dog suddenly collapse? Or has the limp been getting worse for weeks?
Ask for an urgent appointment for a thorough physical exam.

The Veterinary Visit and Dog ACL Tear Diagnosis

Getting a correct diagnosis is vital for planning the best treatment. When you arrive for your vet visit for dog knee injury, the vet will perform several tests.

The Physical Exam

The veterinarian will assess your dog’s overall health first. Then, they will focus on the injured leg. They will gently manipulate the leg to check for instability.

The “Drawer Test”

This is the classic test for a torn ACL. The vet holds the dog’s thigh bone (femur) with one hand and the lower leg bone (tibia) with the other.

If the ACL is intact, the tibia should not move forward significantly relative to the femur.
If the ACL is torn, the tibia shifts too far forward when pulled. This movement is called a “positive drawer sign.” It confirms the joint is unstable.

Other Diagnostic Tools

Sometimes, the drawer test is inconclusive, especially if the dog is tense or the tear is very minor.

Sedation: If the dog is very painful or tense, the vet may suggest mild sedation to perform a more accurate exam.
X-rays (Radiographs): X-rays are standard. They help rule out other issues like bone fractures. They also show the vet if arthritis has already started developing in the joint due to the instability. In some cases, the X-ray can show a small piece of bone pulled away by the ligament (called a tibial avulsion).

Dog ACL Tear Diagnosis Confirmation

A definitive dog ACL tear diagnosis usually relies on the positive drawer sign during the physical exam. X-rays support this by showing secondary changes like joint effusion (fluid) or early arthritis. For most vets, this combination is enough to recommend surgery.

Treatment Options for a Canine CCL Rupture

Once the injury is confirmed, you face a choice in treatment. The decision often depends on the dog’s size, age, activity level, and your budget.

Non-Surgical Management (Conservative Treatment)

Non-surgical care is usually only an option for very small dogs (under 15 lbs) or for dogs whose owners cannot pursue surgery due to cost or health concerns. It aims to manage the resulting arthritis and instability.

Key Components of Conservative Care:

Strict Rest: Months of strict rest are required. This is very hard on many dogs and owners.
Weight Management: Achieving and maintaining an ideal body weight is non-negotiable.
Pain Medications: Long-term use of NSAIDs (Non-Steroidal Anti-Inflammatory Drugs) to manage pain and swelling.
Physical Therapy: Water therapy or controlled exercises might be introduced later to build muscle mass around the joint.

The Downside: Even with the best conservative care, the joint remains unstable. This almost always leads to progressive arthritis and chronic dog hind leg lameness. Often, dogs who don’t have surgery end up tearing the ACL in the other leg later on.

Surgical Repair

Surgery is the gold standard treatment for most dogs with a confirmed ACL tear. Surgery stabilizes the knee joint, allowing healing and reducing painful friction within the joint capsule.

There are several main surgical techniques used to treat a dog CCL rupture signs:

1. Tibial Plateau Leveling Osteotomy (TPLO)

TPLO is one of the most common and successful methods for moderate to large, active dogs.

The Goal: TPLO changes the angle of the top of the shin bone (tibial plateau). When the angle is corrected, the forward slipping motion is stopped, even without the ACL present.
The Procedure: The vet makes a precise, curved cut in the top of the tibia. They rotate that piece of bone into a new position and secure it with a plate and screws.
Recovery: This surgery requires a long, strict recovery period.

2. Tibial Tuberosity Advancement (TTA)

TTA is another common technique, especially effective for active, large-breed dogs.

The Goal: Similar to TPLO, TTA changes the mechanics of the joint. It moves the attachment point of the patellar tendon forward. This counteracts the natural forces that cause the tibia to slide forward.
The Procedure: The vet cuts a section of the tibia bone near where the tendon attaches and moves it forward. It is held in place with a plate and screws.

3. Extracapsular Repair (Lateral Suture Technique)

This technique is older but still used, often for smaller or older dogs that may not be good candidates for the major bone cuts of TPLO or TTA.

The Goal: This procedure uses a strong synthetic material (like heavy fishing line or specialized suture) placed outside the joint capsule to mimic the function of the torn ACL.
The Procedure: The strong suture is looped around the femur and attached to the tibia, holding the bones together tightly. Over time, the dog’s own tissues start to create scar tissue that stabilizes the joint.

Post-Surgery Care and Dog ACL Surgery Recovery

No matter which surgery is chosen, success depends heavily on strict adherence to the post-operative plan. Dog ACL surgery recovery is a marathon, not a sprint.

The First Two Weeks (Initial Healing Phase)

This phase focuses on pain control and preventing the dog from damaging the repair.

Strict Crate Rest: Absolutely no running, jumping, or rough play. Leash walks only for bathroom breaks.
Pain Management: Medications (NSAIDs, sometimes gabapentin) must be given exactly as prescribed.
Incision Care: Keep the incision clean and dry. Watch for excessive swelling, redness, or discharge. Use an Elizabethan collar (cone) to prevent licking.

Weeks 3 to 8 (Controlled Exercise Phase)

The bone begins to heal, and controlled movement can start.

Short, Controlled Leash Walks: Walks should be slow and short, usually 5 to 15 minutes, several times a day. Focus on walking only, not sniffing or playing.
Physical Therapy Introduction: Your vet may recommend starting passive range-of-motion exercises or gentle swimming sessions with a certified canine rehabilitation practitioner. This helps prevent muscle atrophy and stiffness.

Months 2 to 6 (Strengthening Phase)

This is when muscle mass is rebuilt, which is vital for long-term joint health.

Gradual Increase in Activity: Slowly increase the duration and intensity of walks.
Therapeutic Exercises: Introduce controlled trotting on a leash. If TPLO was performed, the vet will monitor bone healing with follow-up X-rays before allowing more vigorous activity.
Avoidance: No high-impact activities (like jumping, chasing balls, or sudden starts/stops) should occur before the 4-to-6-month mark, depending on the surgery type and breed.

Long-Term Prognosis

With proper surgical stabilization and dedicated rehabilitation, most dogs have an excellent long-term prognosis. They can often return to a good quality of life and moderate activity levels. However, due to the underlying predisposition for ligament issues, there is always a risk of tearing the ACL in the opposite knee. Monitoring weight and maintaining fitness is key to preventing future issues related to dog hind leg lameness.

Recognizing Signs in Puppies and Older Dogs

The dog ACL tear symptoms can look different depending on the dog’s age.

Puppies and Young Dogs

ACL tears in puppies are often related to developmental issues or a sudden, high-impact accident.

What to Watch For: You might see acute dog limping after activity that seems severe.
Diagnosis Nuance: In young dogs, the bone growth plates are still open. This can sometimes make the standard drawer test unreliable. The vet must consider this during the dog ACL tear diagnosis.

Senior Dogs

Older dogs often have chronic, low-grade instability that finally gives way.

What to Watch For: Stiffness when getting up, reluctance to exercise, and subtle dog favors back leg movement are common. Owners often mistake this for “just getting old.”
Treatment Considerations: Surgery might be riskier due to concurrent health issues (like heart or kidney disease). Non-surgical management paired with joint supplements and pain control might be the primary choice if the dog is less active.

Differentiating ACL Tears from Other Dog Rear Leg Injuries

It is easy to see signs dog injured CCL and jump to that conclusion, but several other problems can cause similar dog hind leg lameness. A proper vet visit for dog knee injury is essential to rule these out.

Potential Injury	Key Distinguishing Feature
Hip Dysplasia	Pain is usually felt higher up, often causing a “bunny hop” gait rather than isolated knee instability.
Luxating Patella	The kneecap visibly pops in and out of place, often causing a brief skip before the dog kicks the leg out to fix it. Common in small breeds.
Soft Tissue Strain	Generally improves quickly (within days) with rest. The knee joint remains stable on the drawer test.
Nerve Impingement	May cause dragging of the foot (knuckling) without significant pain upon joint manipulation.

Managing Weight: The Role of Nutrition in Prevention

Obesity is a major driver of ACL tears. If your dog has already had one tear, keeping weight off the other leg is paramount to preventing the second injury.

Calorie Control: Work with your vet to determine the exact number of calories your dog needs daily. Don’t rely only on the feeding guide on the bag.
Appropriate Food: Switch to a prescription weight loss diet or a high-quality senior food if recommended.
Supplements: Glucosamine, chondroitin, and omega-3 fatty acids are often recommended to support joint health during and after recovery. They help maintain the cartilage that buffers the bones.

Frequently Asked Questions (FAQ)

Can a dog walk normally right after tearing its ACL?

It is rare for a dog to walk perfectly normally immediately after a complete ACL tear. They will usually exhibit significant lameness, often refusing to put any weight on the leg. In cases of a very small partial tear, they might just show mild, intermittent limping or dog limping after activity.

How long does it take for a dog to recover from ACL surgery?

Dog ACL surgery recovery is lengthy. For most major procedures like TPLO or TTA, full recovery and return to normal, unrestricted activity take 4 to 6 months. Strict rest is enforced for the first 6 to 8 weeks.

If my dog has one torn ACL, will the other one tear?

Yes, there is a high risk. Studies show that 40% to 60% of dogs who tear one ACL will eventually tear the ACL in the opposite knee. This is due to shared underlying biomechanical factors or the increased strain placed on the healthy leg after the first injury.

Is ACL surgery always necessary for dogs?

For medium to large dogs, surgery is strongly recommended to provide long-term stability and reduce the risk of severe secondary arthritis. Non-surgical management is usually reserved for tiny dogs or dogs with severe underlying health issues that make anesthesia unsafe.

How much does dog ACL surgery cost?

The cost varies widely based on location, the specific technique used (TPLO is usually more expensive than an extracapsular repair), and whether the vet practice includes physical therapy in the package. Costs generally range from \$2,500 to over \$6,000 per knee. Always get a full estimate during the dog ACL tear diagnosis appointment.