DOGS AND CATS · OWNER EDUCATION
Patellar Luxation in Dogs and Cats
Patellar luxation means the kneecap slips out of the groove where it should move. Repeated slipping can alter walking and contribute to joint pain and arthritis.
THE SHORT VERSION
What matters for your animal?
Start with the warning signs and when-to-contact sections if your animal is unwell. The same outward change can have several causes, so this guide helps you prepare questions rather than identify a diagnosis on your own.
What is this condition?
Patellar luxation means the kneecap slips out of the groove where it should move. Repeated slipping can alter walking and contribute to joint pain and arthritis.
A luxating patella moves out of its normal position in the knee. Some dogs and cats skip briefly and then use the leg again, while others develop more persistent discomfort or instability. The examination evaluates how readily the kneecap moves and how the whole limb functions. Management depends on the individual problem; a brief return to normal walking does not establish that the knee is structurally normal.
Which species does this guide cover?
The species listed above are the focus of this guide, rather than a complete list of every animal that can develop this condition. Causes, testing and treatment may differ between species and individual patients.
Patellar luxation occurs in dogs and cats. Cats may show difficulty jumping or intermittent skipping; dogs may briefly carry a hind leg. The grade, discomfort, limb alignment and effect on daily activity guide the choice between monitoring and surgery.
Why can it happen?
- Developmental alignment differences are common, especially in small dogs; trauma can also cause instability.
What might an owner notice?
- Intermittent skipping or briefly carrying a hind leg, a crouched gait, reluctance to jump, or persistent limping.
How is the problem investigated?
A joint examination grades the instability and checks for other problems. Radiographs help assess bone alignment and arthritis when treatment planning requires them.
Imaging provides information about location, size, shape, and structural changes. Radiographs and ultrasound often answer different questions, so one does not simply replace the other. Images may reveal a complication or guide sampling without establishing the exact microscopic cause. Some procedures require sedation or anesthesia to obtain accurate images safely. Ask what the proposed study is expected to clarify and how its possible results would influence treatment, further testing, or referral.
What might treatment involve?
Mild stable cases may be monitored with weight and activity management. Painful or function-limiting cases may need surgery to improve alignment.
A movement problem can involve pain, instability, weakness, or more than one of these. Relieving pain is important, but restoring comfortable function may also require changes in activity, body condition, footing, or the home environment. The suitable level of exercise depends on the diagnosis; complete inactivity and unrestricted activity can both be inappropriate in particular situations. Ask for practical instructions about movement and handling, along with the medication plan. Rechecks assess function as well as the outward appearance of the affected area.
This is an overview, not a prescription or a recommendation for a specific individual animal.
What can owners do at home?
Keep weight appropriate and follow a controlled exercise or rehabilitation plan. Report changes in how often the leg slips.
Comfort is assessed through behavior and function as well as obvious crying or vocalization. Changes in posture, movement, grooming, sleep, social interaction, or willingness to be handled can be useful clues. Compare the animal with its own normal behavior rather than with another animal. Keep a short record of what it can do comfortably and share changes with the care team. If pain control appears inadequate, contact the veterinarian; increasing a dose or combining medicines without advice can introduce serious risks.
Avoid actions that could make care less safe.
- Do not repeatedly push the kneecap into place or assume a sudden limp is the known luxation.
What can the longer-term outlook involve?
The outlook is often good with an appropriate plan, although arthritis or recurrence can occur.
A recheck is not simply a repeat of the first appointment. It assesses whether the original problem is improving, whether complications are appearing, and whether the treatment remains appropriate. The useful measures may include comfort, function, intake, body weight, examination findings, or selected tests. Ask which changes are expected before the visit and which should trigger an earlier call. Improvement in one sign does not always mean that every part of the disease has resolved.
Can risk be reduced?
Responsible breeding and healthy weight can reduce some risks. Developmental anatomy cannot be corrected by supplements.
When should you arrange care?
- A persistent limp needs evaluation; severe pain, swelling or sudden inability to bear weight requires prompt care.
Seek urgent veterinary advice if you notice:
DO NOT DELAY URGENT CARE- Seek urgent care for severe pain, major swelling or sudden inability to bear weight.
What information helps the care team?
Write down when changes started, what makes them better or worse, actual food and water intake, and all medicines and supplements. Short videos and a medication-label photo can help describe changes that may not appear during the appointment.
How should you understand the tests?
Ask what each proposed test is intended to answer. Some tests identify a cause; others assess severity, organ function or treatment safety. Results are interpreted with the examination and history. A normal result does not exclude every problem, and an abnormal result does not always explain every sign.
Questions to ask before leaving
- What is confirmed, and which other explanations are still being considered?
- What changes should we expect with the proposed plan, and when should we reassess if they do not occur?
- Which observations should I record, and which changes mean I should call sooner?
- What medicine or home-care problems should I report, and what are the instructions for a missed dose or suspected side effect?
- When is the recheck, what will it assess, and whom should I contact after hours?
A care plan may be adjusted as results or the response become clearer. Keep the written instructions and tell the team if cost, handling or administration difficulty makes the plan hard to follow.
Sources behind this guide
Patellar luxation | Cornell University College of Veterinary MedicineVeterinary, university or animal-health guidance ↗Merck Veterinary Manual: Patellar Luxation in Dogs and CatsVeterinary, university or animal-health guidance ↗Content last reviewed: October 4, 2026. Review status: veterinary-informed; independent veterinarian review not yet completed.