Luxating Patella in Dogs: Grades, Signs and Treatment

By Tailwisp Editorial TeamUpdated October 17, 20263 min read

A small dog who suddenly skips on one back leg and then carries on as if nothing happened may have a luxating patella.

What it is

The patella, or kneecap, normally slides in a groove at the end of the thigh bone. In a luxating patella, it slips out, usually toward the inside (medial luxation) and sometimes the outside. When it pops out, the leg cannot straighten properly until it slips back.

Grades

• Grade 1: the patella can be pushed out but slips back on its own
• Grade 2: it pops out occasionally with flexing and returns spontaneously or by manipulation
• Grade 3: it is out most of the time, but can be replaced
• Grade 4: it is permanently out and cannot be replaced

Higher grades tend to cause more lameness and joint damage.

Who is at risk

Toy and small breeds such as Chihuahuas, Pomeranians, Yorkshire terriers, Maltese, toy poodles and Boston terriers are commonly affected, and the condition is often inherited. Large breeds can have it too. See small breed health concerns.

Signs

• Sudden skipping or hopping on a hind leg
• Holding the leg up for a few steps
• Occasional yelp when the kneecap slips
• Bow-legged stance in severe cases
• Stiffness or reluctance to jump
• Lameness that worsens over time

See why is my dog limping.

Diagnosis

Your vet will examine the knee, feeling for patellar movement, and may take X-rays to assess grade and look for bone changes and arthritis. Some vets recommend orthopedic referral for severe cases.

Treatment

• Conservative management for lower grades: weight control, low-impact exercise, joint support and pain relief when needed
• Surgery for higher grades or persistent lameness: usually deepening the groove and realigning the tendon attachment
• Rehabilitation after surgery with controlled walks and physical therapy

Ask your vet whether surgery is advisable for your dog, since timing and technique matter.

Linked problems

Dogs with luxating patella are at greater risk of cruciate ligament injuries. See cruciate ligament tear in dogs. Chronic instability can also lead to arthritis. See arthritis in dogs.

Home care

1. Keep your dog lean. See dog obesity risks
2. Avoid slippery floors, using rugs and nail care.
3. Limit jumping off furniture and use ramps.
4. Provide steady exercise such as leash walks.
5. Monitor changes and recheck regularly.

Breeding and prevention

Genetic factors are strong. Ask breeders about patellar screening in parents, which is often done by orthopedic exam. See health tests breeders should do.

Common mistakes

• Ignoring skipping because it comes and goes
• Letting weight increase
• Letting small dogs jump from heights
• Delaying surgery in higher grades

Troubleshooting

• My dog skips only occasionally: record episodes and mention at the next visit.
• Skipping is more frequent: book a recheck.
• My dog limps after surgery: contact your surgeon.

A simple plan

1. Get the knees examined.
2. Control weight.
3. Limit jumping.
4. Discuss surgery if grade or signs are significant.

Real-life examples

A Chihuahua with occasional skipping stays comfortable with weight control. A Pomeranian with grade 3 luxation recovers well after surgery. A poodle develops a cruciate tear after untreated instability. Early assessment helps.

Protecting small joints

A few small changes at home can protect knees for years.

Questions to ask your vet

Ask what grade your dog has, whether both knees are affected, how likely progression is, which exercises are safe and what the surgical options and costs are. Ask whether physical therapy could help in lower grades and which signs mean you should return sooner.

Protecting the knee at home

Keep nails short so paws grip, add rugs on slippery floors, block access to high furniture and teach your dog to use steps or ramps. Avoid games that involve sudden twisting or repeated jumping, and favor steady walking and swimming to keep muscles strong.

The takeaway

Luxating patella is common in small dogs. Monitor the grade, manage weight and consider surgery when signs persist.

This article is general educational information, not veterinary advice. Every dog is different. If your dog is unwell, or you are unsure about a symptom, diet change or medication, contact your veterinarian.