What is Legg-Calve-Perthes in Dogs?


Legg-Calve-Perthes Disease or LCPD is an orthopaedic disease that occurs in humans and dogs and refers to the spontaneous degeneration of the femoral head (the ball segment) at the top of the femur leg bone, this degeneration causes the bone to die leading to arthritis within the joint and the eventual collapse in the shape and strength of the bone.

LCPD goes by several names, including aseptic or avascular necrosis of the femoral head, Calve-Perthes disease or Legg-Perthes disease, it is a congenital disease that causes degeneration of the hip joint.

Below you can see the femoral head on the right has degenerated, lost shape and worn irregularly. This would cause the dog to limp and struggle with many movements.

Left – Normal Femoral Head.
Right – Femoral Head with Necrosis Deterioration.
Left – Normal Femoral Head.
Right – Femoral Head with Deterioration.

Animals affected by LCPD will ultimately require surgical treatment if they are to keep using the affected limb.

What dogs are affected by LCPD?

Commonly found in small dogs, typically those under 20 lbs this disease affects mostly terrier type breeds and toy breed dogs. Legg-Calve Disease affects both female and male dogs with equal frequency.

Although lameness is most frequently observed in dogs between five and eight months old, it can appear as late as 18 months or as early as three months.

Often, the limping begins gradually and tends to progress over several weeks. Eventually, it causes the dog to shift weight to the unaffected leg. However, lameness and pain are known to develop suddenly in some LCPD cases. Legg-Calve-Perthes disease should not be confused with Hip Dysplasia, a condition common in larger breeds and older dogs.

Although Terriers are most affected, LCPD affects at least 26 breeds (see the list at the bottom of this post).

Causes of Legg-Calve-Perthes 

Also known as LCP or LCPD, Legg-Calve-Perthes Disease is an excruciating process that only gets worse and more uncomfortable over time. Dogs suffering from LCPD tend to favour the affected leg, and eventually, they will stop using it altogether. This lack of use can cause muscular atrophy and leads to deformation of the leg.

The exact cause is unknown, but researchers have linked it to blood supply issues. The lack of an adequate supply of blood to the thigh bone (femur) leads to necrosis of the femoral head. With necrosis the head breaks down becoming brittle and in turn, causes the gradual disintegration of the hip joint’s bone and cartilage.

Legg-Calve-Perthes is a hereditary disease that typically affects small breed dogs in their early years. In rare cases, trauma can cause the disease.

Has your dog got LCPD?

Symptoms of Calve-Perthes Disease

Whilst Legg-Perthes Disease tends to primarily affect toy and terrier breeds, every dog owner should know the signs to look for because there are cases where the disease has shown up in other dog breeds and there is also the fact that many of the outward signs bear very similar problems to Hip Dysplasia.

LCP disease will cause your dog to limp and favor the affected leg. Often, the limping will begin gradually. It will progress over several weeks, and eventually, it will cause the dog to avoid placing any weight on the sick leg. In some cases, however, the symptoms can develop quite suddenly. 

In opposition to Hip Dysplasia, Legg-Calve-Perthes rarely affects both hips and legs, so most affected dogs usually limp around on one rear leg.

It can be very painful for a dog when the affected leg is manipulated or handled, particularly during the later stages of Legg-Calve-Perthes Disease.

As the LCP-induced lameness progresses, and the dog increasingly favours (doesn’t use) the affected leg, the hip muscles and thigh region will begin to shrink as they lose muscle mass due to lack of exercise and non-use, this will lead to atrophy in the affected leg.

Calve-Perthes Disease Diagnosis

Your vet will review any comprehensive medical history of your pet and will want to know from you the frequency and duration of the symptoms. Then he will perform a physical examination, particularly on the affected joint area and leg. If he suspects a problem then an x-ray or similar may be needed.

In the early stages of LCPD, the bone’s normal density in the femoral head might be diminished. Besides the decreased bone density, the X-ray might show widening of joint space and thickening of the femoral bone. Over time, the femoral head top surface will become misshapen and flattened as the underlying bone and cartilage collapse.

The Left Hip is Normal
The Right Hip shows Deterioration of the Ball (Femoral) and Socket Joint

If your dog has Calve-Perthes Disease, the radiographs will indicate degenerative changes to the neck of the femur, the femoral head, and in the case of more advanced disease stages a collapsed femoral head.

In advanced LCPD cases, the X-ray may show extreme femoral head deformation and the formation of new bone in the affected area. A femoral neck fracture is also a possibility and the socket may show signs of wear due to the rubbing from the incorrect shape of the femoral head.

Legg-Perthes Treatment

Without medical attention, your four-legged friend is likely to suffer from a painful hip area and possibly arthritis. Most likely, your vet will recommend an operation called a Femoral Head and Neck Osteotomy (FHNO). FHNO surgery is also referred to as Femoral Head and Neck Excision (FHNE) and involves the removal and replacement of the affected section of hip-bone. 

Femoral head and neck excision involves removing the ball of the ball and socket joint of the hip.

X-ray of Femoral head removed

Once the affected hip bone section has been removed, the vet fills the space with fibrous tissue and creates a ‘false’ joint. The false joint won’t be as flexible as a natural one, but it will at least allow your dog to move without pain. For a couple of weeks following surgery, physiotherapy will be necessary to help the dog start using the limb again.

The joint is replaced by fibrous tissue. Keeping this fibrous union flexible in the early post-operative period is key to success.

Small dogs generally do quite well with Femoral Head and Neck Excision surgery. An alternative treatment method for Calve-Perthes disease is hip replacement. However, this option is often recommended only for large breed dogs as they don’t do so well with the hip joint excision surgery. Hip replacement operations are usually done by specialist vets.

A common problem with some Retriever breeds in this x-ray the joint has been replaced

After surgery, the dog will still need medication and physical therapy to aid their recovery. Often, dogs receive a regime of pain medication, and vets may recommended they stay on chondroprotective agents like glucosamine in the long-term as that helps in protecting the cartilage. 

Conclusion

Generally, follow-up check-ups are recommended every two weeks. That ensures the medication, exercise and physiotherapy are working as anticipated. Patience is required because overall recovery could take between three and six months.

With proper treatment, pain medication and physiotherapy, your dog is likely to respond and recover well enough to perform routine physical activities. Once the surgical wound has healed, and the false hip formed, the dog should be capable of walking without pain.

However, some dogs may continue to limp even after recovery because of the artificial hip joint, but not due to pain. In fact, many dogs make excellent recoveries such that it can be difficult even to tell that they initially had a problem.

Remember that affected dogs are not ideal for breeding.

Breeds affected by Legg-Calve Perthes

Affenpinscher
Australian Terrier
Bichon Frise
Border Terrier
Boston Terrier
Cairn Terrier
Chihuahua
Cocker Spaniel
Dachshund Fox Terrier
Jack Russell Terrier
Lakeland Terrier
Manchester Terrier
Miniature Pinscher
Miniature Schnauzer
Pekingese
Pomeranian
Poodle
Pug
Schipperke
Scottish Terrier
Shetland Sheepdog
Silky Terrier
Welsh Terrier
West Highland White Terrier
Yorkshire Terrier

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