Knee issues in dogs can cause limping, stiffness, difficulty standing, an unusual sitting position and reluctance to run, jump or use stairs. Common problems include cranial cruciate ligament disease, patellar luxation, meniscal injuries and osteoarthritis.

What owners commonly call a dog's knee is known to vets as the stifle joint. It is one of the most important weight-bearing joints in the hind leg and depends on several bones, ligaments, cartilage structures and muscles working together.

A dog limping on a back leg does not necessarily have a knee problem. Hip disease, spinal conditions, muscle injuries and even a damaged paw can produce similar changes in movement. Persistent or significant lameness therefore deserves veterinary assessment rather than diagnosis at home.

What Are the Most Common Knee Problems in Dogs?

The most important knee conditions in dogs include:

• Cranial cruciate ligament disease: weakening and partial or complete rupture of one of the major stabilising ligaments inside the knee.
• Patellar luxation: movement of the kneecap away from its normal position.
• Meniscal injury: damage to one of the cartilage-like structures within the knee, commonly associated with cruciate ligament disease.
• Osteoarthritis: progressive disease involving cartilage, bone and other structures within the joint.
• Traumatic injuries: fractures, dislocations and soft-tissue injuries can also affect the knee.

The symptoms overlap considerably. Establishing exactly which structure is affected is therefore important before deciding how the problem should be treated.

How Does a Dog's Knee Joint Work?

The canine knee, or stifle, is formed principally by the femur in the upper leg and tibia in the lower leg. The patella, commonly called the kneecap, sits at the front of the joint.

Inside the knee are two important cruciate ligaments. The cranial cruciate ligament and caudal cruciate ligament help control movement between the femur and tibia and contribute to joint stability.

The joint also contains two menisci. These crescent-shaped structures sit between the femur and tibia and contribute to load distribution, shock absorption and joint function.

The ends of the bones are covered by articular cartilage, while synovial fluid helps lubricate the moving surfaces. Muscles and tendons surrounding the joint also contribute to stability and movement.

When one component fails, particularly the cranial cruciate ligament, the mechanics of the entire knee can change.

What Is Cranial Cruciate Ligament Disease in Dogs?

Cranial cruciate ligament disease is one of the most important causes of hind-leg lameness in dogs. The cranial cruciate ligament, commonly shortened to CrCL or CCL, is an important stabiliser within the knee.

People sometimes describe the condition as a dog's ACL tear because the equivalent ligament in the human knee is called the anterior cruciate ligament. However, canine cruciate disease often develops differently from the classic sporting ACL injury seen in people.

The American College of Veterinary Surgeons guide to cranial cruciate ligament disease explains that in many dogs the ligament gradually degenerates over time before partially or completely rupturing. Factors including genetics, joint conformation, physical condition and body weight can contribute.

Does a Dog Have to Injure Their Knee to Tear the Cruciate Ligament?

No. Although traumatic rupture can occur, many canine cruciate problems are associated with progressive degeneration of the ligament rather than one dramatic accident.

An owner may notice the limp immediately after running or playing and naturally assume that activity caused the injury. In some dogs, however, the ligament may already have been weakened before the final fibres failed.

Partial tears can be particularly difficult to recognise because the dog may experience intermittent or relatively mild lameness before the ligament deteriorates further.

Which Dogs Are More at Risk of Cruciate Disease?

Cruciate disease can affect dogs of different sizes and breeds. Risk is influenced by several factors rather than one single cause.

Breed predispositions have been identified, and excessive body weight and poor physical condition are recognised modifiable risk factors. Research involving dogs attending primary-care veterinary practices in England also found increasing body weight within breeds to be associated with increased odds of a cruciate disease diagnosis.

Maintaining an appropriate body condition cannot guarantee that a dog will avoid cruciate disease, but it is one factor owners can directly influence.

What Happens to the Knee When the Cruciate Ligament Fails?

When the cranial cruciate ligament can no longer stabilise the joint normally, abnormal movement can occur between the tibia and femur during weight bearing.

This instability causes pain and contributes to progressive changes within the joint. Osteoarthritis can subsequently develop and progress.

The altered mechanics can also place the meniscus at risk of injury.

What Is a Meniscal Tear in Dogs?

The menisci help distribute load and provide shock absorption within the knee. The medial meniscus is particularly vulnerable when the knee becomes unstable following cranial cruciate ligament rupture.

A damaged meniscus can contribute to persistent or recurrent pain. Some owners report hearing or feeling clicking from an affected knee, although a clicking sound alone cannot diagnose a meniscal injury.

What Is a Luxating Patella in Dogs?

A luxating patella occurs when the kneecap moves out of the groove in which it would normally track.

Most canine patellar luxations are medial, meaning the kneecap moves towards the inside of the leg, although lateral luxation can also occur.

The condition is particularly associated with smaller dogs, although larger breeds can also be affected.

Why Does My Dog Skip on One Back Leg?

One characteristic sign of patellar luxation is an intermittent skipping gait. A dog may suddenly carry one back leg for several steps before extending the limb and beginning to use it normally again.

This can occur when the patella temporarily moves out of position and subsequently returns to its normal location.

However, skipping does not prove that a dog has a luxating patella. A veterinary orthopaedic examination is needed to establish the cause.

Are All Luxating Patellas Serious?

No. Patellar luxation is graded according to severity, and the effect on individual dogs varies considerably.

Some dogs with mild luxation experience relatively few clinical problems, while severe cases can result in persistent lameness, skeletal deformity and progressive joint disease.

The American College of Veterinary Surgeons information on patellar luxation explains that diagnosis is primarily based on detecting an unstable kneecap during an orthopaedic examination, with additional investigations used when necessary.

Can Dogs Get Arthritis in Their Knees?

Yes. Osteoarthritis commonly affects the canine knee and frequently develops secondary to another orthopaedic problem.

Cruciate ligament disease is an important example. Instability and abnormal loading alter the environment within the joint and can lead to progressive osteoarthritic changes.

Patellar luxation, previous trauma and other abnormalities can also contribute.

Osteoarthritis is not simply cartilage becoming worn out. It is a progressive disease involving multiple structures within the joint and can result in pain, stiffness and reduced function.

Once significant osteoarthritis has developed, treatment focuses on managing the disease and maintaining comfortable function rather than claiming to restore the knee to its original condition.

What Are the Signs of Knee Problems in Dogs?

A dog with a knee problem may limp, avoid putting full weight through one hind leg, struggle to stand, sit with one leg positioned unusually or become reluctant to run, jump or climb stairs.

Possible signs include:

• Sudden or gradual hind-leg limping
• Holding one back leg off the ground
• Stiffness after resting
• Difficulty getting up
• An intermittent skipping gait
• Sitting with one hind leg extended to the side
• Reluctance to jump into the car
• Hesitation on stairs
• Reduced interest in running or playing
• Swelling around the knee
• Loss of muscle in the affected leg
• Clicking or popping associated with movement
• Pain when the leg is moved or handled

Dogs do not need to cry or whine for a knee condition to be painful. A persistent change in gait is itself important.

If your dog is limping but otherwise eating, playing and behaving normally, read our guide explaining why a dog may limp but still act normally.

Could My Dog's Back Leg Problem Be Something Other Than the Knee?

Yes. A limp tells you that your dog is altering the way they use a limb, but it does not identify which structure is responsible.

Similar symptoms can result from:

• Hip dysplasia or hip osteoarthritis
• Paw injuries or foreign bodies
• Torn or damaged nails
• Muscle and tendon injuries
• Spinal disease
• Neurological disorders
• Fractures or other trauma
• Arthritis affecting another joint

Owners can sometimes identify an obvious paw injury, but repeatedly bending or manipulating a painful knee at home is not advisable. An orthopaedic examination is a safer way to localise the source of lameness.

How Do Vets Diagnose Knee Problems in Dogs?

Diagnosis begins with the dog's history and a physical examination. Your vet may ask whether the lameness appeared suddenly or gradually, whether it changes after exercise or rest and whether there was an obvious injury.

Watching the dog walk can provide valuable information. The vet may then examine the paws, muscles and individual joints to determine where discomfort originates.

How Is Cruciate Ligament Disease Diagnosed?

When cruciate disease is suspected, the vet assesses the stability of the knee. Two important findings are abnormal cranial drawer movement and cranial tibial thrust.

These tests assess abnormal movement between the tibia and femur. Muscle tension can make instability difficult to detect in some dogs, particularly with partial ligament damage, so sedation may sometimes be required for a thorough examination.

Radiographs cannot show the cruciate ligament itself in the same way they show bone, but they can reveal joint swelling, osteoarthritis and other changes while helping exclude alternative causes of lameness.

More advanced investigation may occasionally be needed.

How Are Knee Problems in Dogs Treated?

Treatment depends on the diagnosis. A dog with a mild luxating patella may require a very different plan from a large active dog with a completely ruptured cranial cruciate ligament.

Does a Dog With a Torn Cruciate Ligament Need Surgery?

Surgery is frequently recommended for cranial cruciate ligament disease because it addresses the mechanical instability within the knee.

Several surgical approaches are available. The most appropriate procedure depends on factors including the dog's size, age, activity, anatomy and the surgeon's assessment.

What Is TPLO Surgery?

TPLO stands for tibial plateau levelling osteotomy. Rather than replacing the damaged cruciate ligament, the procedure changes the geometry of the upper tibia to alter the forces acting through the knee during weight bearing.

This can provide functional stability despite the damaged cranial cruciate ligament.

TPLO is widely used, particularly in medium and larger dogs, but it is not automatically the correct operation for every patient. Your vet or orthopaedic surgeon can explain the advantages, risks and alternatives for your individual dog.

What Other Cruciate Operations Are Available?

Other procedures include tibial tuberosity advancement, commonly called TTA, and extracapsular stabilisation techniques.

There is no single surgical procedure that should automatically be selected based only on the words cruciate tear. Dog size, activity, knee anatomy and surgeon experience all influence treatment decisions.

Can a Cruciate Injury Be Treated Without Surgery?

Non-surgical management may be considered in selected dogs, particularly depending on size, health, degree of instability and individual circumstances.

Management can involve controlled activity, weight management, veterinary pain relief and structured rehabilitation.

However, pain medication does not correct mechanical instability within a cruciate-deficient knee. Owners considering conservative management should therefore discuss the likely outcome and limitations with their vet rather than assuming rest alone will repair a completely unstable joint.

How Is a Luxating Patella Treated?

Treatment depends on severity and clinical signs. Dogs with mild luxation and few symptoms may be monitored and managed conservatively, while persistent lameness, significant deformity or more severe luxation can lead to consideration of surgery.

Surgical treatment may involve correcting several anatomical factors contributing to the kneecap moving out of position.

What Role Does Rehabilitation Play?

Rehabilitation can be important after knee injury and surgery. Controlled exercises can help restore muscle strength, improve limb use and support recovery.

The rehabilitation programme should match the diagnosis and stage of healing. More activity is not always better, particularly during early recovery after surgery.

Why Is Weight Management Important for Dogs With Knee Problems?

Every additional kilogram of unnecessary body weight increases the mechanical demands placed on weight-bearing joints.

This is particularly important when a knee is already unstable, injured or arthritic.

Weight management also provides owners with something practical they can influence. Measure meals, account for treats and monitor body condition rather than relying on body weight alone.

If your dog's activity has been substantially restricted following a knee injury, their calorie requirements may also decrease. Continuing to feed the same amount despite a major reduction in activity can result in unwanted weight gain during recovery.

For more information on nutrition and body condition, read our guide to the best foods for dogs with joint problems.

Can Joint Supplements Help With Dog Knee Problems?

Joint supplements can provide nutritional support as one part of a wider mobility plan, but it is important to understand their limitations.

A supplement cannot mechanically stabilise a ruptured cranial cruciate ligament or physically return a severely luxating patella to normal alignment.

Ingredients used in canine joint formulations include glucosamine, collagen, green-lipped mussel, hyaluronic acid, chondroitin and omega-3 fatty acids. Evidence varies between ingredients and formulations.

Where supplements are used, they should complement appropriate veterinary treatment, healthy body condition and suitable exercise rather than delay diagnosis or replace treatment for a structural knee problem.

What Can I Do at Home to Help a Dog With Knee Problems?

Follow the exercise restrictions provided by your vet, particularly following a cruciate injury or surgery. Allowing a dog to run because they suddenly appear more comfortable can disrupt recovery.

Useful home changes can include:

• Place non-slip rugs on smooth floors.
• Keep food, water and beds easy to access.
• Provide a supportive bed.
• Use a lead for controlled toilet trips when activity is restricted.
• Prevent uncontrolled running and jumping during recovery.
• Keep nails appropriately trimmed to improve grip.
• Maintain a healthy body condition.
• Follow rehabilitation exercises exactly as instructed.
• Watch for increasing swelling, pain or deterioration in limb use.

Dogs that develop secondary arthritis may also benefit from environmental changes covered in our guide to making the home more comfortable for a dog with arthritis.

For senior dogs experiencing more general mobility changes, our guide to helping an older dog with stiff joints provides additional practical advice.

When Is a Dog's Knee Problem an Emergency?

A mild intermittent limp generally requires veterinary assessment rather than emergency treatment, but sudden severe symptoms need more urgent attention.

Contact a vet promptly if your dog:

• Suddenly cannot bear weight on a leg
• Appears to be in severe pain
• Has suffered significant trauma
• Has an obviously deformed or severely swollen limb
• Suddenly cannot stand or walk normally
• Develops weakness, dragging or loss of coordination in the hind legs

Weakness or paralysis can indicate a neurological or spinal problem rather than a knee injury and requires prompt veterinary assessment.

A Practical Knee and Mobility Care Checklist

Frequently Asked Questions About Knee Issues in Dogs

How Can I Tell if My Dog Has a Knee Problem?

Possible signs include hind-leg limping, stiffness, difficulty getting up, an unusual sitting position, a skipping gait and reluctance to run or jump. These signs can also result from hip, paw, muscle and spinal problems, so veterinary examination is needed to identify the cause.

What Is the Most Common Knee Injury in Dogs?

Cranial cruciate ligament disease is one of the most important and common causes of knee-related hind-limb lameness in dogs. Unlike many human ACL injuries, canine cruciate disease frequently involves progressive degeneration of the ligament.

Can a Dog Walk With a Torn Cruciate Ligament?

Yes. Some dogs can still walk with partial or complete cruciate ligament damage, although they may limp or avoid fully loading the affected leg. Being able to walk does not mean the knee is stable or pain-free.

Will a Dog's Cruciate Ligament Heal by Itself?

A completely ruptured cranial cruciate ligament does not simply return to normal mechanical function through rest. Scar tissue and surrounding structures can provide some secondary stability, particularly in selected smaller dogs, but persistent instability can contribute to pain and osteoarthritis. Treatment decisions should be made with a vet.

Why Does My Dog Lift a Back Leg for a Few Steps and Then Walk Normally?

An intermittent skipping action can occur with patellar luxation, where the kneecap temporarily moves away from its normal position. Other problems can produce intermittent lameness, so this movement alone cannot confirm the diagnosis.

Can Knee Problems Cause Arthritis in Dogs?

Yes. Osteoarthritis commonly develops secondary to knee conditions that alter normal joint mechanics, particularly cranial cruciate ligament disease. Patellar luxation and previous trauma can also contribute to degenerative joint changes.

Should I Walk My Dog if They Have a Knee Injury?

Exercise depends on the diagnosis. A dog recovering from cruciate surgery may require strictly controlled lead walking, while another condition may require a different programme. If a knee injury is suspected but has not yet been diagnosed, avoid strenuous exercise and seek veterinary advice rather than attempting to exercise through the problem.

Can an Overweight Dog Be More Likely to Have Knee Problems?

Excess body weight increases the mechanical load placed through the knees and is a recognised risk factor for cranial cruciate ligament disease. Maintaining an appropriate body condition is therefore an important part of protecting mobility and managing existing joint disease.

The Bottom Line

Knee issues in dogs can range from intermittent kneecap instability to significant cruciate ligament disease and progressive osteoarthritis. The symptoms often overlap, and a back-leg limp cannot reliably tell you which structure is responsible.

Pay attention to changes in the way your dog walks, sits, stands and gets up. Persistent limping, recurring skipping, stiffness or reluctance to use a leg deserves veterinary assessment.

Once the cause is established, treatment may involve weight management, controlled exercise, pain management, rehabilitation or surgery. The right approach depends on the individual dog and the specific problem within the knee.

Most importantly, do not wait for your dog to cry before taking lameness seriously. Dogs with painful knee disease can remain bright, hungry and interested in life while quietly changing the way they move.

This article provides general educational information and does not replace examination, diagnosis or treatment from a veterinary professional.