Legg-Calve-Perthes Disease (LCPD) in dogs was named after three doctors who in 1910 played very critical roles in its discovery and treatment in children. They are Dr. Arthur Legg, an American Orthopedic Surgeon; Dr. Jacques Calvé, a French Orthopedic Surgeon and Dr. Georg Perthes, a German Orthopedic Surgeon.
The hip joint connects the hind/rear limbs to the trunk of the body. It is made up of a ball (head of thigh bone) in a socket (hip/acetabulum) which gives it the name “ball and socket joint.” Legg-Calve-Perthes is an orthopedic (skeletal system) disease that affects the head of the thigh bone. Thus, the ball in the socket is diseased, leading to a weak joint.
LCPD shouldn’t be confused with Canine hip dysplasia or Coxofemoral/hip luxation. Canine hip dysplasia occurs when there’s an abnormal development of the hip joint, which causes a partial dislocation of the femur head and manifests with various degrees of lack of resilience.
Coxofemoral luxation occurs when there’s dislocation of the femur from the acetabulum or simply removal of the thigh bone from the hip joint.
Even though LCPD also affects children between the ages of four to ten years, it is not zoonotic – your dog can not transmit the disease to you.
What is Legg-Calve-Perthes Disease?
Legg-Calve-Perthes Disease (LCPD) is a degenerative/chronic disease in dogs that affects the head of the femur (thigh bone), causing the hip to collapse. LCPD occurs when there’s interrupting blood supply to the head of the femur.
The synovial blood vessels are mainly the ones compromised in this condition. This leads to the death of the cells in the head of the femur and causes the articular cartilage to collapse. This autonomous deterioration leads to arthritis.
Legg-Calve-Perthes Disease (LCPD) is also called Avascular/Aseptic (interrupted blood supply) Necrosis (death) of the Femur head. The disease goes by different names such as Perthes disease, Calve-Perthes disease, Legg-Perthes disease, Osteochondritis juvenilis, and coxa plana.
What causes LCPD is idiopathic (without a known cause). Even though various hypotheses (possibilities/speculations) have been proposed with genetics being a key factor. Legg-Calve-Perthes Disease’s exact cause remains unknown. Aside from genetics, other theories include hormonal factors, increased pressure within the joint. These can occur after trauma and anatomic disorder.
Signs of Legg-Calve-Perthes Disease in Dogs
The main sign associated with LCPD in dogs is limping, which leads to lameness. This starts gradually, without any underlying trauma, and often exacerbates in weeks. During this stage, the dog can no longer place any weight on the affected leg resulting in lameness.
In other dogs, lameness can develop suddenly without any limping. Lameness of the affected leg leads to the loss of muscle mass, a secondary condition known as “disuse atrophy.” This occurs when a particular body part is not being used – as in this case, the affected/lame limb.
Other signs include chewing on the affected limb or hip area due to the pain. The presence of pain might lead to a lack of appetite, general body weakness, and unresponsiveness. Dogs can suddenly or gradually become aggressive or anxious too as the pain progresses.
Sometimes, there can be sounds on joint movement too. Usually, signs of LCPD start manifesting between five to eight months of age, especially in small breed dogs and dogs predisposed to the disease.
It is rare to see Legg-Calve-Perthes Disease affecting both limbs/hips, but it can occur. Always remember that limping and lameness in dogs can be caused by a wide variety of factors and disease conditions, and it is appropriate to take your dog to see the vet once you notice this sign.
Characteristics and Predisposed Dogs
Small dog breeds that are less than 9 kilograms (19.84 pounds) are mostly predisposed to Legg-Calve-Perthes Disease.
The disease condition is also common in toy breeds and terriers such as:
- Yorkshire Terrier
- Shetland Sheepdog
- Welsh Terrier
- Cairn Terriers
- Australian Terrier
- Bichon Frise
- Fox Terrier
- Lhasa Apsos
- Border Terrier
- Jack Russell Terrier
- Australian Shepherds
- Boston Terrier
- Scottish Terrier
- Lakeland Terrier
- Toy and Miniature Poodles
- Miniature Schnauzer
- Cocker Spaniel
- Silky Terrier
- Fox Terrier
- Lhasa Apsos
- Border Terrier
- Jack Russell Terrier
The fact that these dog breeds are predisposed to the disease does not mean all dogs of these breeds are going to get the disease. Large dog breeds can also be affected by LCPD.
Both male and female dogs are affected equally. LCPD is said to usually affect dogs between five-eight months, but it can be seen as early as three months or as late as the 18th month (adolescent dogs).
What is the Next Course of Action if my Dog is Diagnosed with LCPD?
All hope is not lost if your dog is diagnosed with LCPD. If your dog’s lameness is mild, your dog will be given pain medication to help relieve the pain and make the dog as comfortable as possible.
In severe cases, your veterinarian may recommend surgery. The two major surgeries performed are Femoral Head and Neck Osteotomy (FHO) and Total Hip Replacement (THR).
In FHO, the head of the femur is removed surgically, and the body is allowed to heal by producing scar tissues. This scar tissue mimics the original joint tissue, and a new but false joint is created.
In THR, implants are inserted to stimulate a functional hip. This is primarily done in larger dogs with LCPD. Usually, THR is reserved as the last choice when surgery is to be done due to its high cost.
After a successful surgery, your dog will still need physical therapy such as swimming, leash walking, and other activities that do not require vigorous use of the limb. Physical therapy is done after healing has occurred.
Your dog will also be put on pain medication to get back to everyday life. Dogs stay on chondroprotective drugs for a long time to help protect the cartilage, e.g., glucosamine. It is important to ensure that your dog does not become obese to cause strain and stress on the hip joint.
Overall recovery may take between three to eight months if all the above factors are taken into consideration. Some dogs recover faster or later than others depending on their general body condition, genetics, and immune system response.
Complications involving both surgeries are rare, even though the surgeries are risky. Major complications that arise are limping or discomfort at the site of surgery. Sometimes, a second surgery is needed to remove any residual bone fragment that will be causing the discomfort.
Some dogs avoid using the corrected affected limb because they do not feel the ball in the socket. Such dogs are supposed to be trained post-operatively to learn how to use the legs.
Other complications that can occur are implant loosening, infection, nerve damage, and hip displacement or luxation.
Prevention of LCPD in Dogs
Since there’s no known cause of LCPD in dogs, prevention has been very tricky. However, from the various hypotheses surrounding the disease, genetics seems to be on the highest rank. Therefore, the only known preventive method is to avoid breeding affected dogs or their parents.
Also, radiographs should be taken of every dog once LCPD has been discovered in a breeding line until after ten months old before breeding will be done.
Legg-Calve-Perthes surgeries are performed by well-specialized veterinary orthopedic surgeons. Femoral Head Osteotomy is usually recommended for small logs, while Total Hip Replacement is recommended by large breed dogs.
Femoral Head Osteotomy
Femoral Head Osteotomy (FHO) or Femoral Head and Neck Excision (FHNE) is performed by removing the head and neck of the femur (osteo – bone + tomy – cut). FHO is done to relieve the pain on mobility since the two bones (femur head and acetabulum) won’t be in contact during movement.
The muscles of the hip, pelvis, and thigh will hold the femur in place without it falling off. With time, scar tissue will form where the femur head was to replace the cartilage. This connects the femur to the acetabulum and creates a false joint with better mobility than the disabled hip.
Since the pressure on the hip joint is moved to the pelvis, the FHO limb is slightly shorter than the normal leg. This, however, doesn’t affect the normal usage of the limb.
Total Hip Replacement Surgery
THP is done to replace both the femoral head and the acetabulum with artificial parts (prostheses / prosthetic device). This prosthetic device is a combination of titanium (metal) with ultra-high-molecular-weight polyethylene (plastic). In this type of surgery, there is a metal ball at the top of the femur that fits into a dense plastic socket that replaces the acetabulum.
These prostheses are then held together by special bone cement. Some prostheses can be used without the bone cement (cementless implants) and some occur as a hybrid between the two – cemented implants and cementless implants.
Recently, technological advancement to Total Hip Replacement includes the BFX Lateral Bolt System, which stabilizes the implant by using biologic fixation of bony ingrowth into the implant. This has been proved effective for long-term stabilization.
The surgeon, alongside the dog owner, will decide which of the implants will be used for the surgery. Complete recovery may take a year.
The Latest Research on LCPD
Studies believe that blood that flows to the hip becomes interrupted, leading to clot formation within the affected blood vessels. This reduces blood flow to the hip, leaving the hip weakened due to lack of oxygen and nutrients being carried by the blood, and it begins to degenerate. This causes minor fractures.
With time, scar tissue, which is not as stronger and elastic as the previous tissue, will attempt to correct the damage and stabilize the broken bones. This leads to changes in the structure of the bone and predisposes the animal to arthritis.
Small Nucleotide Polymorphism (SNP) Array Technology is being used by researchers at Clemson University in South Carolina to help identify the gene marker responsible for the disease. If a genetic marker is found, genetic tests can be done for breeders to help detect which dog carries the gene and is predisposed to the disease.
The research involves extracting DNA from the blood samples of affected dogs and using the SNP array technology to identify differences in the DNA between affected dogs and healthy dogs.
Legg-Calve-Perthes Disease (LCPD), also called Avascular Necrosis of the Femur head, is caused by interruption of blood supply to the head of the femur which leads to its death. Affected dogs and their parents should not be used for breeding as the disease is being proposed to be of genetic origin.
Animals with LCPD after surgery and physical therapy live a long, happy, fulfilled life, returning to normal functions after a few months.
Speak to your veterinarian if your dog is limping. They are the best people to diagnose or rule out this disease. Early diagnosis can increase the medical chances of your dog.
Akosua is a Veterinary Medical Student at the University of Ghana. She likes writing during her free time and sharing her knowledge about veterinary medicine (she found the perfect combo here 🙂 ). Her passion is to inspire Veterinary professionals and change the perspective of animal love in developing countries through her work and writing.