Luxating Patella in Dogs: Signs, Grades and Treatment
Vet verified. Written by Corinne Homer, Copywriter. Reviewed by Dr. Linda Simon MVB MRCVS, Team Vet.
A luxating patella means the kneecap moves out of the groove where it should track. Some dogs show an occasional skip and then walk normally again. Others have persistent lameness, pain or changes in the shape and function of the leg. A veterinarian needs to examine the knee because a cruciate injury, hip problem, fracture and other orthopedic conditions can look similar.
Do not try to push a kneecap back into position at home. Record when the gait change happens, restrict rough activity and arrange an examination. Sudden inability to bear weight, major trauma, severe pain, swelling, collapse or a cold paw needs urgent veterinary care.
What is a luxating patella?
The patella is the kneecap. It normally glides within a groove at the lower end of the thigh bone as the knee bends and straightens. With patellar luxation, the kneecap shifts to the inside or outside of that groove. Medial luxation, toward the inside of the leg, is most common in small dogs, but dogs of any size can be affected.
Merck Veterinary Manual describes patellar luxation as a developmental orthopedic disorder associated with abnormal development of structures around the knee. The alignment of the hip, thigh bone, shin bone, muscles and tendon can all influence how the kneecap tracks. Trauma can also destabilize a previously normal knee.
Symptoms of a luxating patella
The classic sign is an intermittent skip. A dog may carry a rear leg for a few steps, stretch it backward and then resume a normal walk. That pattern is useful information, but it does not confirm the diagnosis. Signs can include:
- Briefly holding up one rear leg
- A skipping, hopping or uneven gait
- Shaking or extending the leg before walking normally
- Reluctance to run, jump, climb stairs or rise
- Stiffness after rest
- Pain when turning or during activity
- A crouched rear posture or bowed-looking leg
- Persistent lameness in more advanced cases
Dogs do not always cry when a joint hurts. Slowing down, sleeping more, hesitating at stairs or shifting weight forward can be pain behavior. Keep a dated log and take short videos without encouraging extra running.
Causes of a luxating patella
Most cases are related to development and leg alignment rather than one bad step. A shallow groove, rotation of the shin bone, angle of the thigh bone and the pull of the quadriceps mechanism can contribute. The problem may be present in one knee or both. Less commonly, a traumatic injury can cause patellar luxation.
Over time, repeated displacement can irritate cartilage and contribute to arthritis. An unstable knee can also place abnormal forces on other structures. A dog with patellar luxation can still develop a separate cranial cruciate ligament injury, so a sudden worsening deserves a fresh exam rather than an assumption that the familiar kneecap caused it.
What breeds are prone to a luxating patella?
Toy and small breeds are commonly represented, including Pomeranians, Chihuahuas, Yorkshire Terriers, Miniature Poodles and Boston Terriers. Larger dogs can be affected too, and lateral luxation may be seen more often in some large dogs. Breed only changes probability. It does not replace an orthopedic examination.
Because inherited structure can contribute, affected dogs should be discussed with a veterinarian before breeding. A normal-looking walk at one moment does not rule out a kneecap that moves intermittently.
When to see a veterinarian
Book an appointment for any recurring skip, limp, reluctance to move or change in activity. Seek same-day or emergency care when the dog cannot bear weight, the leg looks deformed, pain is severe, swelling develops quickly, a wound is present or the problem follows a fall, collision or other trauma.
Until the dog is assessed, use a leash for bathroom trips, block stairs and jumping, and provide traction. Do not repeatedly flex the knee, force a stretch or test how far the dog can walk. Never give ibuprofen, naproxen, acetaminophen or another human pain reliever unless a veterinarian specifically directs it.
How veterinarians diagnose patellar luxation
The veterinarian watches the dog stand and walk, feels the patella and evaluates the rest of the limb. The kneecap is graded according to how readily it moves, whether it returns to the groove and how much it affects alignment. The exam also checks hips, cruciate stability, muscle symmetry, paw placement and pain.
X-rays can help evaluate bone alignment, arthritis and other causes of lameness. More advanced imaging or referral to a veterinary surgeon may be recommended when surgery is being planned or the anatomy is complex. The grade is only one part of the decision. Pain, frequency of lameness, age, activity, body size, concurrent disease and structural change also matter.
Treatment for a luxating patella
Treatment ranges from monitoring and rehabilitation to surgery. A dog with infrequent signs and little discomfort may be managed conservatively under veterinary supervision. Persistent pain, frequent lameness, progressive deformity or a higher-grade luxation makes surgical consultation more likely.
Mild luxating patella: Grades 1 and 2
In grade 1, the kneecap can usually be moved out of the groove during examination but returns on its own. Grade 2 tends to move out more easily and may remain displaced for part of the time. These descriptions do not automatically mean a dog is pain-free or that surgery is unnecessary.
A conservative plan may include maintaining a lean body condition, controlled activity, veterinary rehabilitation and prescribed pain control when needed. Exercise is individualized. Total rest can reduce strength, while uncontrolled jumping, sharp turns and slippery-floor sprints may aggravate signs.
Severe luxating patella: Grades 3 and 4
In grade 3, the kneecap is displaced most of the time but may be returned manually during an exam. In grade 4, it is permanently displaced and cannot be returned normally. More pronounced bone and soft-tissue changes are often present, and the dog may have persistent gait abnormalities.
Higher grade does not tell the whole story, but it increases concern about mechanical dysfunction and progressive change. Early specialist input can clarify whether delaying surgery is likely to make reconstruction more difficult.
Surgery for a luxating patella
Surgery aims to realign the kneecap mechanism and keep the patella tracking in an appropriate groove. Depending on the dog, the surgeon may deepen the groove, move the attachment of the patellar tendon, balance soft tissues or correct bone alignment. The exact combination is selected from the examination and imaging.
Recovery requires strict activity control, incision care, medication, rechecks and a staged return to movement. Call the surgical team for worsening swelling, discharge, an open incision, uncontrolled pain, vomiting after medication, fever, sudden non-weight-bearing or any fall during recovery.
What does luxating patella surgery cost?
There is no responsible national flat price. Cost varies with location, one or both knees, imaging, surgeon, implant needs, hospitalization, medication, complications and rehabilitation. Ask for a written estimate that separates the consultation, diagnostics, operation, aftercare and expected rechecks. Pet insurance coverage depends on the policy, enrollment date and whether the condition is considered pre-existing.
Care and prevention
Developmental patellar luxation cannot always be prevented. Good management can reduce avoidable strain and help the veterinary team see changes early. The goal is comfortable function, not proving that a dog can push through a long walk.
Help your dog maintain a lean body condition
Extra body weight increases the load carried by an unstable knee. Ask the veterinarian for a target body-condition score and daily calorie plan. Measure meals by weight when possible, count treats and recheck every few weeks. Weight loss should be gradual and nutritionally complete.
Use diet and supplements carefully
No food or supplement can move a kneecap back into its groove or correct abnormal bone alignment. A complete and balanced diet supports overall nutrition, and a veterinarian may discuss specific joint-support ingredients for an adult dog. That conversation should cover the product, dose, evidence, calories, medications and realistic goal.
Choose controlled walks and useful rest
Follow the veterinary plan for leash walks and rehabilitation. Use rugs or runners on slick floors, a ramp when appropriate and barriers to prevent repeated furniture jumps. Avoid forcing the dog to exercise through a limp. Sudden sharp turns, ball-launching and rough play may be inappropriate during a flare or recovery.
Keep veterinary and rehabilitation rechecks
Rechecks assess pain, muscle, gait and whether the plan still matches the knee. A credentialed veterinary rehabilitation professional can teach safe exercises selected for the individual dog. Do not copy strengthening drills from another dog, especially before diagnosis or after surgery.
Set up the home for safer movement
Place traction from the dog's bed to the door, food and water so normal daily movement does not require crossing slick flooring. Keep nails and paw hair managed for grip, use a supportive harness if the veterinary team recommends one and position bedding where the dog can rest without climbing. A ramp must be stable, nonslip and shallow enough for the individual dog. It is not automatically safer than stairs.
Ask every caregiver to follow the same restrictions. One uncontrolled game, furniture jump or long weekend walk can undo a careful recovery plan. If the dog begins slipping, sitting differently or avoiding a previously comfortable route, record the change and contact the veterinary team rather than adding exercise.
Finch & Barker product boundaries for knee health
Trusted source and related guides
Review the professional overview of patellar luxation from Merck Veterinary Manual. For related symptoms, see our guide to limping without obvious pain and our dog feeding guide.
Frequently asked questions
Should you walk a dog with a luxating patella?
Often, controlled leash walking remains part of an individualized plan, but the amount depends on pain, grade, other injuries and treatment stage. Stop if lameness worsens and follow the veterinarian's instructions.
Can a luxating patella heal on its own?
The developmental alignment problem generally does not correct itself. Signs can come and go, so an apparently normal walk does not prove the knee is stable.
Is a luxating patella an emergency?
An occasional familiar skip may not be an emergency, but sudden non-weight-bearing, severe pain, trauma, swelling or deformity needs urgent assessment.