Legg-Calvé-Perthes Disease

What Is Legg-Calvé-Perthes Disease?

Legg-Calvé-Perthes disease (LCPD), also called avascular necrosis of the femoral head, happens when the blood supply to the ball of the hip joint is interrupted. Without blood flow, the bone in the femoral head weakens, dies back, and collapses, leaving a rough, misshapen joint that hurts. It mostly affects young toy and small-breed dogs between about 4 and 12 months of age, and it is rare in cats.

Breeds seen most often include Yorkshire Terriers, Miniature and Toy Poodles, West Highland White Terriers, Jack Russell Terriers, Miniature Pinschers, Pugs, and Cairn Terriers. A hereditary component is suspected in several of these breeds. In most dogs only one hip is affected, though both sides can be involved.

Signs Owners Notice

• Gradual limping on one back leg that worsens over weeks, sometimes becoming toe-touching or non-weight-bearing
• Pain or crying when the hip is moved or the leg is handled
• Thinner thigh muscles on the affected side
• Chewing or licking at the hip or flank area
• Reluctance to jump, run, or climb stairs

Causes and Risk

The exact reason the blood supply fails is not fully understood. Genetics, hormonal factors during growth, and the anatomy of small-breed hips are all thought to play a role. Trauma is not usually the trigger. Because the condition likely runs in families, affected dogs and their parents are generally not recommended for breeding.

LCPD can look similar to other causes of back-leg lameness in small dogs, especially a luxating patella (kneecap that slips) or hip dysplasia. Some dogs have more than one problem at once, which is why a careful orthopedic exam and X-rays matter.

Diagnosis

Your vet will feel and move the hip, check for pain and muscle loss, and rule out knee problems. Hip X-rays usually show the classic changes: a flattened, irregular, or moth-eaten femoral head and a widened joint space. Very early cases may look subtle, so repeat X-rays a few weeks later are sometimes needed. Sedation helps get clear, comfortable images.

Treatment and Outlook

• Femoral head and neck ostectomy (FHO): the most common treatment. The damaged ball is removed and a fibrous false joint forms, which small dogs tolerate very well.
• Total hip replacement: occasionally offered in specialty centers, though less common for very small dogs.
• Conservative care: rest and pain relief can help a few very mild cases, but most dogs still need surgery eventually.
• Rehabilitation: controlled walks, range-of-motion exercises, and sometimes underwater treadmill work rebuild muscle after surgery.

Most dogs are using the leg well within six to eight weeks of FHO and do very well long term, especially with diligent physical therapy and a lean body weight. In the US, FHO typically costs roughly $1,500 to $4,000 depending on region and whether a specialist performs it.

Practical Tips for US Pet Owners

• Do not wait out a limp in a young small-breed puppy for more than a few days; book an exam.
• Ask whether a board-certified surgeon or rehab practitioner is available nearby for post-op care.
• Keep your dog slim to reduce load on the healing hip.
• Find a nearby practice through veterinary clinic listings.

Key Takeaways

• LCPD is collapse of the femoral head from lost blood supply, mainly in small breeds under a year old.
• It causes progressive back-leg limping and muscle loss.
• FHO surgery plus rehab gives most dogs an excellent outcome.

FAQ

Is Legg-Calvé-Perthes disease painful?
Yes. The collapsing joint is painful, which is why most dogs limp and some refuse to use the leg.

Can a dog live normally after FHO?
Most small dogs walk, run, and play normally after recovery, particularly with good rehab and weight control.

Is it the same as hip dysplasia?
No. Hip dysplasia is a loose, poorly formed joint; LCPD is death of bone in the femoral head from lost blood supply.