Luxating Patella in Dogs: Signs, Grades and Treatment

What it is

The patella, or kneecap, normally glides in a groove at the end of the thighbone as the knee bends. In patellar luxation it slips out of that groove. Medial luxation, toward the inside of the leg, is the more common type, particularly in small and toy breeds. Lateral luxation, toward the outside, is less common and seen more in large breeds. It is usually a developmental problem, partly inherited, and signs often begin before a dog is a year old. Occasionally it follows an injury. About half of affected dogs have both knees involved.

Vets grade it from 1 to 4. In grade 1 the kneecap can be popped out by hand and slips back in. In grade 2 it pops out on its own and goes back with a little help. In grade 3 it stays out most of the time but can be pushed back. In grade 4 it is permanently out and cannot be put back by hand.

The classic sign is a skip: your dog runs, lifts a back leg for a few steps, then walks normally again. Some dogs kick the leg out to snap the kneecap back. Mild cases are often painless, but over time the knee can wear and become painful. If your dog has an on-and-off limp, limping in dogs lists other possible causes.

Causes and risk factors

Cause	What it means
Developmental problem with how the knee and leg align	The groove, muscles, and bones around the knee do not develop normally; the exact cause is usually unclear.
Inherited tendency	Evidence suggests a partly genetic basis, and OFA says it should be considered an inherited disease.
Small and toy breeds	Medial luxation (toward the inside) is most common; sources name Chihuahuas, Pomeranians, Yorkshire Terriers, Maltese, and others.
Large and giant breeds	Lateral luxation (toward the outside) is seen more in large breeds than small ones, though medial luxation still occurs; OFA names Great Danes, Saint Bernards, and Irish Wolfhounds.
Other limb problems	Hip dysplasia, bowed femurs, or excessive angulation can contribute and make treatment harder.
Trauma to the knee	An injury occasionally causes luxation in dogs with normal anatomy.
Excess weight	Extra weight adds strain on the knee, and VCA recommends weight loss for overweight dogs.

What you can do at home

Mild luxation often causes little pain, and many small dogs live comfortably with it, but any dog with skipping steps should see the vet for a grade and a plan. In the meantime, a few sensible steps help. Keep your dog at a healthy weight, since extra weight adds strain to the knee. Choose controlled exercise, such as steady leash walks. Keep a record of how often skipping happens, ideally with a short phone video, to show your vet.

Watch for changes: skipping that becomes more frequent, a limp that no longer goes away, a leg carried up more often, or signs of pain can mean the condition is progressing or a ligament has been injured. VCA notes joint supplements and mobility diets may slow the progression of arthritis, but ask your vet before starting any.

Never give human pain medicines such as ibuprofen, naproxen, or acetaminophen on your own. The FDA warns they can cause stomach ulcers, kidney damage, and liver damage in dogs. Use only the pain relief your vet prescribes. After surgery, follow the rest and physical therapy plan exactly; several weeks of restricted activity is typical.

What happens at the vet

Your vet diagnoses patellar luxation mainly by feeling the knee: moving the kneecap to see whether it slips out of the groove and how easily it goes back. That exam sets the grade. X-rays, sometimes with sedation, show how severe the problem is and check for other issues such as hip dysplasia, and a CT scan may help plan surgery when the bones are misshapen. The vet also checks the knee ligaments, because luxation makes cruciate ligament tears more likely.

Treatment depends on grade, signs, and age. Dogs with no signs or mild grade 1 luxation may need only monitoring, weight management, controlled exercise, and sometimes physical therapy or anti-inflammatories prescribed by the vet. Surgery is generally recommended for grade 2 and above with frequent luxation or worsening lameness, and sooner rather than later for higher grades. Surgeons may deepen the groove, realign the shin bone attachment, tighten or loosen soft tissue, or correct bone shape, often in combination.

Outcomes are good to excellent when surgery happens before arthritis develops, and recovery usually involves several weeks of rest followed by follow-up X-rays. Arthritis, once established, cannot be reversed. Large dogs and dogs with other limb problems have a more guarded outlook.

Prevention

Because patellar luxation is a developmental condition that is at least partly genetic, you cannot prevent it in an individual puppy. The American College of Veterinary Surgeons advises that dogs diagnosed with it should not be bred. If you plan to breed, the Orthopedic Foundation for Animals (OFA) keeps a patellar luxation database for dogs 12 months and older. The vet examines the dog awake and classifies it, and normal dogs receive an OFA number. Periodic re-exams are recommended since some luxations appear later in life.

If you are getting a puppy, ask the breeder whether the parents were screened. For any dog, the best step is catching it early. Mention any skipping to your vet at routine visits, keep your dog lean, and stick with controlled exercise. Early diagnosis lets you and your vet choose between monitoring and surgery before arthritis sets in, which is when outcomes are best. Because luxation makes cruciate ligament tears more likely, take any new limp seriously. See arthritis in dogs for what long-term joint wear looks like.

Frequently asked questions

What are the grades of luxating patella?

There are four. In grade 1 the kneecap can be popped out by hand and slips back. In grade 2 it pops out on its own and returns with a little help. In grade 3 it stays out most of the time but can be pushed back. In grade 4 it is permanently out and cannot be repositioned by hand.

Can a luxating patella heal on its own?

The shape of the groove and the alignment of the leg do not correct themselves. Mild grade 1 cases may be tolerated for life, and weight management, controlled exercise, and physical therapy can ease signs, but Merck notes that conservative care does not correct the underlying anatomy.

Does my dog need surgery for a luxating patella?

Not always. Dogs with no or mild signs are often monitored. Surgery is generally recommended for grade 2 and higher, frequent luxation, or worsening lameness, and sooner rather than later for higher grades. Your vet will advise based on your dog.

Is a luxating patella painful?

Mild cases are often painless. As the condition progresses, the kneecap can wear the cartilage and arthritis can develop, which causes pain. Dogs with luxation are also more likely to tear a knee ligament.

Which breeds are prone to luxating patella?

Small and toy breeds such as Chihuahuas, Pomeranians, Yorkshire Terriers, Boston Terriers, Maltese, Bichon Frises, and Miniature Poodles are commonly affected. Larger breeds including Great Danes, Irish Wolfhounds, Saint Bernards, Akitas, and Great Pyrenees can also be.

Written from veterinary sources by the Pawsplained editorial team. Not yet reviewed by a veterinarian; this is general information, not a diagnosis or treatment plan. Updated Oct 30, 2026. Editorial policy