Luxating Patella in Dogs: What Is It, and How Is It Treated?

If your dog suddenly skips a step, holding up their back leg briefly before walking normally again, a luxating patella could be the reason. This common dog knee problem, which is usually inherited, occurs when the kneecap slips out of its normal groove. In other words, a dog with patellar luxation has a dislocated kneecap.  

Luxating patella in dogs can be mild, causing only occasional skipping, or more severe, leading to pain, ongoing lameness, and arthritis. Depending on the severity, luxating patella treatment can range from lifestyle changes to medication to surgery. Your veterinarian can recommend the best approach for your individual pet’s situation. 

What Is a Luxating Patella in Dogs?

A luxating patella in dogs—also called a dislocated knee—is a common condition in which the kneecap (patella) shifts sideways (luxates) away from its normal position at the front of the knee. 

Patellar luxation can affect one or both knees in dogs. In mild or intermittent cases, the kneecap may briefly slip out of its groove and then return to place on its own. In more severe cases, the kneecap may remain out of place, making the leg stiff and difficult to extend.

Medial Patellar Luxation vs. Lateral Patellar Luxation 

About 75% of the time, the patella tends to dislocate toward the inside of the knee, or toward the other hind limb. This version of a luxating patella is called medial patellar luxation (MPL) and is more common in smaller dogs. 

Sometimes the dislocation occurs toward the outside of the knee, or away from the other leg. This condition is known as a lateral patellar luxation (LPL). 

Although both small and large dogs are more likely to have MPL than they are to have LPL, most cases of LPL occur in larger dogs.   

Symptoms of a Luxating Patella in Dogs

The main symptom of a luxating patella in dogs is the sudden lifting of one hind limb while walking or running.   

In this brief, sudden limp, a dog will hold their hind limb off the ground for a short period of time before walking normally again. The affected leg may be held close to the body or extended backward. This is often termed a “skip” by pet parents and vets. 

Some dogs will yelp when this occurs, but others will show no signs of discomfort aside from the sudden, short-lived limp. 

Other symptoms of luxating patella in dogs include: 

• Limp that comes and goes 
• Bowlegged stance in the hind limbs 
• Hunched lower back 
• Cracking or popping noises when the knee is bent 

In some cases, the dog’s knee(s) are permanently luxated, meaning they’re always dislocated. These dogs appear to have a stiff, awkward, bowlegged gait. With the kneecap permanently out of place, the leg won’t extend properly. 

Your vet will combine these symptoms with the findings of their physical exam to make a definitive diagnosis. 

What Causes Patellar Luxation in Dogs?

A luxating patella in dogs is generally hereditary and has to do with the unusual knee anatomy of dogs that are affected. 

In some cases, trauma causes the luxation. 

Although obesity does not directly cause a luxating patella in dogs, it can contribute to the severity of the disease and can increase complication rates if surgery is pursued. 

Many small-breed and large-breed dogs are predisposed to having a luxating patella, including: 

Small-Breed Dogs 

• Affenpinscher 
• American Water Spaniel 
• Boston Terrier 
• Brussels Griffon 
• Chihuahua 
• English Toy Spaniel 
• Japanese Chin 
• Lancashire Heeler 
• Löwchen 
• Maltese 
• Manchester Terrier 
• Mi-Ki 
• Miniature Pinscher 
• Miniature Wirehaired Dachshund 
• Papillon 
• Pekingese 
• Pug 
• Shih Tzu 
• Smooth Haired Fox Terrier 
• Tibetan Spaniel 
• Toy Poodle 
• Yorkshire Terrier 

Large-Breed Dogs 

• Akita 
• Chinese Shar-Pei 
• Flat-Coated Retriever 
• Great Dane 
• Great Pyrenees 
• Irish Wolfhound 
• Newfoundland 
• Saint Bernard 

How Do Vets Diagnose a Luxating Patella in Dogs?

Usually, a physical exam is the only thing needed to diagnose a luxating patella in dogs. 

In fact, a luxating patella is often diagnosed incidentally during a routine wellness exam, or during an exam for a different problem. 

A luxating patella in dogs can also show up on imaging like X-rays, CT scans, or MRIs, but these diagnostics are not usually used to make the diagnosis. 

How Is Luxating Patella in Dogs Treated?

Treatment depends on the severity of the luxation, whether it causes pain or lameness, and your dog’s overall health. Mild or symptom-free cases may only require monitoring or medical treatment, while painful, recurring, or more severe luxations may require surgery to realign and stabilize the knee. 

Medical Treatment for Luxating Patella in Dogs 

Medical treatment can help control pain and support mobility, but it does not correct the underlying alignment problems that cause the kneecap to luxate. Depending on your dog’s symptoms, your veterinarian may recommend: 

• Pain medication: Your veterinarian may prescribe medications, such as Galliprant (grapiprant tablets), to manage pain and inflammation. Galliprant is a daily chewable tablet that can be used at the earliest signs of osteoarthritis in dogs, which is often caused by a luxating patella. 

• Weight management: Maintaining a healthy weight can reduce stress on the knee joint. Your vet may recommend a special diet to help your dog lose weight.  

• Controlled activity: Your veterinarian may recommend limiting running, jumping, stair climbing, and other activities that place stress on the knee. This may include short, leash-only potty walks. 
• Crate rest/confinement: The duration can vary based on the severity of your dog’s condition. Crate rest usually lasts at least six weeks, and sometimes more than 12. 

• Joint supplements: Supplements to support joint health, such as Dasuquin, may be recommended as part of an overall joint-care plan.  

• Physical rehabilitation: Some dogs may benefit from veterinarian-directed exercises or rehabilitation to support muscle strength and mobility. 

Surgical Treatment for Luxating Patella in Dogs 

Pet parents may pursue surgery in severe cases, or in cases where medical treatment has failed. The goal with surgery is to make alterations to the knee joint to help the joint have a more normal anatomy, such as: 

• Changing where certain ligaments attach in the knee (tibial tuberosity transposition) 
• Deepening the groove at the end of the femur that the patella rests in (trochlear wedge resection) 
• Tightening the joint capsule around the knee (lateral capsular imbrication) 

As with any surgery, it comes with risks and the potential for complications. The most common postoperative problem in surgery is that the luxating patella will come back. Other potential complications include: 

• Implant failure (breakage) 
• Under- or overcorrection 
• Avulsions (separations or detachments) 
• Fractures 
• Infections 
• Seromas (fluid-filled pockets) 
• Progressive arthritis 

Large-breed dogs and obese dogs are at higher risk for these issues due to increased strain on the knee joints. 

Recovery and Management of Luxating Patella in Dogs

Medical management of a luxating patella in dogs, meaning the pet doesn’t get surgery, can take several weeks to show improvement. 

This option may also need to be repeated periodically throughout your dog’s life, depending on how often flare-ups occur. Exercise is a common reason for flare-ups, but sometimes flare-ups occur for no apparent reason. Your dog may benefit from long-term NSAIDs, such as Galliprant, to control pain and inflammation associated with the condition. 

Surgical correction has a much longer recovery period—at least eight weeks, often longer. Regular rechecks with the veterinary surgeon are a crucial part of your dog’s recovery after surgery. 

Prevention of Luxating Patella in Dogs

Most dogs with a luxating patella are genetically predisposed to the condition. This means there is nothing a pet parent can do to prevent the condition. 

Although a pet parent cannot prevent most cases of kneecap dislocation, they can help their pet by keeping them at a healthy weight. A healthy body condition slows the progression of arthritis that can result from patellar luxation. 

Traumatic luxation of the kneecap can be prevented by keeping  your dog on a leash or in a fenced yard to prevent injury.