What is Legg-Perthes disease?

This disease is known under several different names.

1. Legg-Calvé-Perthes syndrome
2. Legg-Perthes disease
3. Coxa plana
4. Ischemic necrosis of the hip
5. Aseptic necrosis of the femoral head
6. Osteochondritis and avascular necrosis of the femoral head

Regardless of what your chose to call it, it is characterized by a malformed femur head and hip plain. This disease affects the hip of young puppies, normally between the age of 4 and 12 months. It can lead to osteoarthritis in adults.

The hip bone of a dog consists of so called hip and socket joint, where the top part of the leg bone fits into a socket formed by the pelvic bone. In a dog suffering from Legg-Calvé-Perthes syndrome, degeneration or even necrosis (death) occurs at the growth centre in the ball and socket joint. This leads to significant pain and lameness. The cause behind the degeneration and necrosis is an interrupted blood supply to the femoral head, near the hip joint. (It is actually equivalent to a condition termed avascular necrosis in adult dogs.) The loss of bone mass eventually causes a more or less pronounced collapse of the hip joint.

Breeds with a higher risk of developing Legg-Calvé-Perthes syndrome

Legg-Calvé-Perthes syndrome occurs in small dog breeds, such as miniature and toy poodles.

The exact mode of inheritance is not yet known for Legg-Calvé-Perthes syndrome, but it is suspected to be autosomal recessive with incomplete penetrance. A dog diagnosed with Legg-Calvé-Perthes syndrome should not be used for breeding, and nor should its parents. Sibblings are also suspected carriers.

Legg-Calvé-Perthes syndrome symptoms in dogs

A dog with Legg-Perthes disease will gradually suffer from more and more significant pain and lameness in one of its hind legs. (In some dogs, the hips of both hind legs are affected, but this is very rare.) The symptoms of Legg-Perthes disease will gradually worsen over the course of 3-4 weeks. In the later stages, the puppy is often in a lot of pain and the muscles of the affected leg will show distinct atrophy (shrinkage).

When you bring your dog to the vet, a radiograph can be used to confirm that the pain, lameness and atrophy are caused by Legg-Perthes disease. A radiograph will also show if any other degenerative changes has occurred in the hip. A bone biopsy is often also carried out to confirm the diagnosis.

Legg-Perthes disease treatment for dogs

If Legg-Perthes disease is diagnosed at an early stage, i.e. while the head of the femur is still relatively unchanged, it can be treated by placing the hind leg in a sling for a period of time to prevent it from bearing weight. The veterinarian can also prescribe painkillers to help the dog handle the pain.

In most cases, Legg-Perthes disease is however not diagnosed until the head of the femur has changed a lot and the dog is experiencing severe problems with lameness and ache. In cases where the changes has gone far, the only efficient way of treating Legg-Perthes disease is to surgically remove the necrotic femur head.

Skeletal and muscular disorders in dogs: (click for more info)
Canine hip dysplasia
Congenital vertebral anomalies in dogs
Craniomandibular osteopathy in dogs
Elbow dysplasia in dogs
Hypertrophic Osteodystrophy in dogs
Hypertrophic Osteopathy in dogs
Legg-Calvé-Perthes syndrome in dogs
Luxating patella in dogs
Masticatory muscle myositis in dogs
Masticatory Muscle Myositis (MMM) and Extraocular Myositis (EOM) in dogs
Osteoarthritis in dogs
Osteochondritis Dissecans in dogs
Panosteitis in dogs
Spondylosis in dogs