Patellar Luxation in Dogs: Causes, Symptoms, and What You Can Do

If your dog suddenly lifts a hind leg for a few steps and then continues walking as if nothing had happened, you may have already noticed a case of patellar luxation. What looks like a minor quirk can actually be a serious knee problem. The sooner you recognize it, the better the outlook for your dog.

Have you noticed this “hopping” behavior in your dog, or does he occasionally limp for a short while? Then you’ve come to the right place! In this guide, you’ll learn what patellar luxation is, how to recognize it, and what treatment options are available.

Important: This article is not a substitute for a veterinary diagnosis or treatment. If you suspect patellar luxation, you should always consult a veterinarian who can properly examine your dog’s knee joint.

What is patellar luxation in dogs?

In a nutshell: The patella is the kneecap. In your dog, it sits in a groove at the lower end of the thighbone and ensures that the knee can straighten and bend smoothly. In patellar luxation, the kneecap pops out of this groove.

This occurs in about 75 to 80 percent of cases as an inward dislocation (medial dislocation) and, less commonly, as an outward dislocation (lateral dislocation). Some dogs are affected in only one leg, but often both knees are unstable at the same time.

What causes patellar luxation in dogs?

By far the most common cause is genetics. This means that the dog is born with a congenital knee deformity, such as a groove that is too shallow, a misaligned leg, or weak ligaments. Over time, the patella slips out of place more and more easily.

Less commonly, patellar luxation is caused by an accident, a fall, or a strong impact. This traumatic form can affect any dog, regardless of breed or age.

Which dog breeds are particularly prone to patellar luxation?

The medial form, in which the kneecap pops inward, primarily affects small and toy breeds, such as

• Chihuahua
• Yorkshire Terrier
• Toy Poodle and Toy Spitz
• Jack Russell Terrier
• Pomeranian
• Pekingese
• Boston Terrier

The lateral (outward) form is more common in larger dogs, e.g., in

• Boxer
• Labrador
• Pyrenean Mountain Dog
• Irish Setter or
• Cocker Spaniel.

However, mixed-breed dogs can also be affected. A genetic predisposition can often be detected in puppies as early as four to six months of age. Sometimes, however, it doesn’t become apparent until later, when the dog becomes more active or loses muscle mass as it ages.

What are the typical symptoms of patellar luxation in dogs?

The tricky thing about this condition is that the symptoms often appear briefly and then disappear again.

Many dog owners initially mistake this behavior for a quirk. Pay close attention to these signs:

• Your dog suddenly lifts one hind leg while walking and "hops" for a few steps
• His leg suddenly gives way
• Lameness that comes and goes
• Cracking or clicking sounds in the knee joint
• Stiffness after getting out of bed or after periods of rest
• In more severe cases: The dog consistently avoids putting weight on the affected leg

Some dogs briefly extend their leg backward, shake it, and the kneecap is back in place. Dogs are masters at compensating. They often don’t show signs of pain until it becomes really severe.

Suspected Patellar Luxation – When Should You See a Veterinarian?

Even at the first sign of “hopping” or occasional limping, it’s a good idea to visit the vet. Patellar luxation is a progressive condition: the more often the kneecap pops out, the more the ligaments can stretch—and the faster cartilage wear can progress. Early diagnosis provides clarity and allows for targeted intervention before the knee sustains permanent damage.

The four grades of patellar luxation in dogs

Veterinarians classify patellar luxation into four grades of severity. This classification helps in selecting the appropriate treatment.

• Grade 1: The patella sits normally in the groove. Although it can be manually pushed out of place, it returns to its normal position on its own. The dog usually shows no or very few symptoms.
• Grade 2: The patella occasionally pops out on its own, for example when running or jumping. It returns to its normal position through movement or by straightening the leg. At this stage, many dogs already exhibit the typical limping gait.
• Grade 3: The patella is usually outside the groove but can still be manually pushed back into place. However, it quickly dislocates again. The dog often limps noticeably.
• Grade 4: The patella is permanently dislocated and cannot be reduced. The knee is severely misaligned; the dog often walks with a bent stance or avoids putting weight on the leg altogether.

The higher the grade, the more severe the symptoms—and the greater the risk of developing knee osteoarthritis over time.

How is a diagnosis of “patellar dislocation” made?

The veterinarian will carefully palpate your dog’s knee joint and check whether and how far the kneecap can be moved out of its groove. To do this, they will bend and straighten the leg while applying light pressure and also determine in which direction the patella can be moved.

Especially when surgery is planned, X-rays are also taken to determine the severity of the misalignment and whether signs of joint wear are already visible.

What treatment options are available for patellar luxation in dogs?

How patellar luxation is treated depends on the severity of the condition and how much it affects your dog's daily life.

1. Conservative treatment

For Grade 1 and some cases of Grade 2, conservative treatment is often sufficient. It consists of several components:

• Physical therapy: Targeted exercises strengthen the muscles around the knee and improve joint stability. Underwater treadmills, balance pads, and controlled cavaletti training are popular methods for specifically building up the hindquarters.
• Weight management: Every extra pound puts additional strain on the knee. Maintaining a healthy ideal weight is therefore essential.
• Appropriate exercise: Gentle walks on firm, level ground are ideal. Stop-and-go games, rough play, and jumping should be avoided.
• Anti-inflammatory drugs and pain relievers: During acute episodes, the veterinarian may also prescribe medication to relieve symptoms.

2. Surgery

Surgery is recommended for grade 3 or higher, or in cases of significant symptoms. The specific procedure used depends on the individual findings. Often, the groove is deepened, the ligament alignment is corrected, or the leg axis is straightened.

Surgery is followed by a recovery period of several weeks, during which movement is gradually increased under supervision and accompanied by physical therapy. In the first few weeks, only short walks on a leash are permitted; after that, the level of activity is increased step by step. Following this plan provides your dog with the best chance for a full recovery. The prognosis is generally good, and the sooner the surgery is performed, the better the outcome.

Can patellar dislocation be prevented?

If the condition is genetic, patellar luxation cannot be completely prevented. However, you can significantly reduce the risk of complications:

• When buying a puppy, look for reputable breeders who have their parent dogs screened for patellar luxation.
• Don't overexert young dogs: No long jumps, no rough play, and no stairs during the first few months.
• Make sure to focus on continuous, steady muscle development.
• Maintain a healthy weight.