Patellar Luxation in Dogs

Patellar Luxation in Dogs - Symptoms, Causes, Diagnosis, Treatment, Recovery, Management, Cost

What is Patellar Luxation?

If your dog’s patellar luxation is congenital (present at birth), the affliction may not be noticed until about six weeks of age because it can be mistaken for clumsiness or slow learning. Developmental luxation is usually thought to be from hereditary ligament or skeletal conformation and will be evident as your puppy ages. Any kind of injury to the leg such as a fracture or sprain, can cause immediate patellar luxation that is obvious right away.

The most commonly affected breeds of dog include the Shih Tzu, Toy Poodle, Chihuahua, Maltese, Pomeranian, Yorkshire Terrier, Japanese Chin, Beagle, Pekingese, Basset Hound, Chow Chow, Cocker Spaniel, Australian Shepherd, Chinese Shar Pei, Lhasa Apso, Shiba Inu, and Dachshund. Some large breeds that are affected include St. Bernards, Huskies, Boxers, Malamutes, Akitas, Golden Retrievers, and Labrador Retrievers.

A patellar luxation is a common disorder in which the kneecap is displaced or dislocated from the knee joint where it belongs. This may be a condition the dog has when born (congenital) or may develop later in life (developmental). Although trauma to the knee can cause patellar luxation, it is usually hereditary in nature and affects toy breeds most often.

However, other breeds have been reported as having patellar luxation as well. This condition causes mild to severe pain, depending on which grade of luxation your dog has. Unless it is caused by an injury, the grade starts at 1 (mild) and progresses to 4 (severe) without treatment. If it is caused by an injury, it can start at any grade, depending on the severity of the injury. Patellar luxation is almost always in the rear legs and will cause lameness eventually without treatment, causing a skipping type gait.

Symptoms of Patellar Luxation in Dogs

The symptoms of patellar luxation depend on the cause and the grade of the condition. Most commonly, the signs include:

  • Limping
  • Abnormally carrying leg or legs
  • Inability to bend the knee
  • Pain when moving the leg
  • Will not run or jump
  • Refusing to exercise
  • Swelling
  • Weak legs
  • Crying out in pain when used or manipulated


A patellar luxation comes in four different grades depending on severity. These grades include:

  • Grade 1 – Minimal lateral deviation, no cracking sounds, slight rotation of the tibia, and returns to the original position after extension
  • Grade 2 – Up to 30 degrees of torsion in the tibial crest, frequently moves from its intended position, almost permanently luxated, very difficult but possible to move patella back in place
  • Grade 3 – Flattened knee joint, permanently luxated with a tibial crest of 30 to 50 degrees, still usable but held in a partially flexed position
  • Grade 4 – Permanently luxated with up to 90 degrees deviation, knee joint is flat or convex, unable to use the leg normally

Causes of Patellar Luxation in Dogs

The cause of patellar luxation includes:

  • Congenital – Present at birth
  • Developmental – Develops over time but is considered to be a hereditary deformity or weakness in the ligaments or bones in the knee
  • Traumatic – Results from an injury or accident that damages the knee ligaments or bones

Diagnosis of Patellar Luxation in Dogs

If this is a congenital condition, your puppy will probably be diagnosed at his first appointment with your veterinary professional. However, in the case of hereditary or traumatic patellar luxation, the condition will make itself known when it is at a high enough grade. A physical examination will be performed right away, which will likely include auscultation, palpation, vital signs, lameness assessment, and behavioral analysis. 

Be sure to tell the veterinarian if your pet has been sick or injured recently and if you have given him any medication, even if it is an herbal supplement. Some medications can affect the symptoms and may not interact well with the drug your veterinarian proposes to use for treatment. The veterinarian will run some blood tests such as a blood count and chemical analysis as well as radiography like x-rays, CT scans, ultrasound, and an MRI.

Treatment of Patellar Luxation in Dogs

To treat your dog for patellar luxation, the grade and your dog’s health will be taken into consideration. Surgery is the most obvious and commonly chosen treatment, but the veterinarian may try a leg brace or bandage, cage rest, and medication instead.


The operational technique depends on the grade of the condition and the results vary depending on the cause of the patellar luxation. The veterinarian may choose to use fascial release incisions on the side of the knee or knees affected, soft tissue realignment, inserting pins into the tibia to create a fixed position, or bone shaping to deepen the groove of the femur.


Steroids, NSAIDs, and narcotics can be given for pain and inflammation. In addition, there are supplements such as glucosamine, Vitamin C, Vitamin E, and collagen injections that may be helpful for pain.

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Recovery of Patellar Luxation in Dogs

Your dog’s prognosis is good but depends on the grade of the patellar luxation. In very severe cases, the limb may need to be amputated to stop the pain. Mild to moderate cases are treated with surgery or medication and should return your dog to normal health in no time at all.

Patellar Luxation Questions and Advice from Veterinary Professionals


Lab/Cocker Spaniel Mix




18 Months


0 found this helpful


0 found this helpful

My pet has the following symptoms:
My dog has been diagnosed with a grade 2 luxating patella. However, my current vet doesn't do orthopedic surgery. A lot of other vets in my town have a very cold personality and I dont know if I can trust them with my animal. There is one that is on vacation for 2 weeks that could perform it and I trust. Only other option is to drive over an hour away for his surgery. Just wondering if it would be best to get it done this week or if waiting 2 more weeks would cause more serious complications.

Sept. 18, 2018

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Mix breed




6 Years


8 found this helpful


8 found this helpful

My pet has the following symptoms:
Less Energef
Takes Time To Get In Or Out The Car
It has been 5 days since i found my dog is less energetic although he walks on his four legs,he cant go down the stairs without trying to lift his back legs, but he walks normally but slower than the usual I took him to the vet today and he showed me how easily he moves his leg that has patellar Luxation, he told me to let him take medications for a weak and then decide whether it should be treated medically or by a surgery My question is which grade he has if he walks normally but has a problem in going down the stairs and takes time to sit down as welll going in or outside the car

July 22, 2018

Answered by Dr. Michele K. DVM

8 Recommendations

We grade patellar luxations based on how mobile the kneecap is and where it sits normally, and I can't give you that answer without seeing Russ. If your veterinarian felt that giving him medication for a week and re-evaluating was a valid treatment plan, that makes sense, and we do that for lower grade luxations fairly commonly.

July 22, 2018

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