Hip Dysplasia in Dogs

Hip dysplasia is a fairly common orthopedic problem in dogs that affects the stability and function of the hip joint. It is caused by abnormal growth and development of the joint, which can happen for a multitude of reasons, but mostly due to genetics. Hip dysplasia can affect any dog but is most common in large dogs breeds, including German shepherds, Labrador retrievers, St. Bernards, and rottweilers.

Limping and pain are the most common symptoms of this condition, often starting when the dog is still a puppy. Left untreated, hip dysplasia tends to progress to osteoarthritis and further degeneration of the hip joint. Fortunately, there are several treatment options to improve the quality of life for dogs with hip dysplasia.

What Is Hip Dysplasia?

The hip joint in dogs, as well as in cats, humans, and most other mammals, is a ball-and-socket joint that includes two main components:

1. Femoral head: a ball-shaped formation at the top of the femur (thigh bone)
2. Acetabulum: a rounded socket in the pelvic bones

In a normally functioning hip joint, the femoral head sits within the acetabulum and moves smoothly with the assistance of cartilage and joint fluid. The joint is secured with ligaments. The joint capsule provides stability, produces fluid, and holds the fluid in the joint to provide lubrication.

When a dog has hip dysplasia, the hip joint does not develop properly. The femoral head fits poorly in the acetabulum (or not at all) and there is laxity in the hip joint, meaning a looseness in the joint that leads to instability. Because of the instability, movement of the leg causes excess friction in the joint, leading to further deformity. Over time, the cartilage in the joint wears down.

The damaged hip joint eventually develops osteoarthritis, including abnormal bony growths called osteophytes. The damage in the joint limits the dog's range of motion and makes it gradually more difficult for the dog to move the leg without pain.

Symptoms of Hip Dysplasia in Dogs

Although some dogs with severe hip dysplasia start showing symptoms when they are only a few months old, it is more common for symptoms to appear when the dog is one to two years of age. However, some dogs with only mild hip laxity don't show symptoms until they are much older and arthritis has caused additional degeneration of the hip joint.

Signs of hip dysplasia often appear gradually and vary depending on the severity of the disease. The earliest signs are generally weakness of the hind legs, along with pain, that shows in the dog's reluctance to get up from a sitting or lying position, climb stairs, or jump up onto a couch or other height.

Often, you'll notice that your dog seems okay at the beginning of a play session, but is limping by the time it is over. The dog might have an odd run, somewhat like a hop. The dog might seem to shift its weight more heavily over its front legs than its back legs, or might be reluctant to walk altogether.

Be aware that there are other causes of limping in dogs, so should your dog become lame, you should always consult your veterinarian.

Causes of Hip Dysplasia

Several factors may contribute to the development of canine hip dysplasia. The primary cause is heredity, however, meaning that the dog is born with a tendency towards this trait. Another contributing factor is rapid growth, often due to dietary factors, such as overfeeding your puppy. This is part of the reason many owners of large breeds choose specially formulated large breed puppy food. Ask your veterinarian if large breed food is right for your puppy.

Although obesity does not cause hip dysplasia, it can significantly increase the symptoms. If your dog is predisposed to hip dysplasia or has been diagnosed, be sure to keep its weight under control in order to minimize symptoms.

Several dog breeds are predisposed to hip dysplasia, most of which are large-breed dogs. The following are just a few of the dog breeds prone to hip dysplasia: 

• Labrador Retrievers
• Golden Retrievers
• German Shepherds
• Rottweilers
• Great Danes
• Mastiffs
• American Eskimo
• Boxer

Diagnosing Hip Dysplasia in Dogs

When you bring your dog to the vet for lameness or hip pain, your vet will begin by thoroughly examining your pet. This will include manipulation of the joints and observation of your dog's gait. Next, your vet will recommend radiographs (x-rays) of your dog's hips, back legs, and possibly spine. Proper positioning during the x-rays is extremely important in order to obtain an accurate diagnosis. This may be difficult for many dogs, especially those in pain. Most dogs need to be sedated for properly positioned radiographs.

Both the examination and radiographs are essential in order to accurately diagnose canine hip dysplasia. An experienced veterinarian can recognize the condition from the laxity of the hip joint during palpation and manipulation, along with characteristic abnormalities in the x-rays.

Treatment

If your dog is diagnosed with hip dysplasia, there are several treatment options. Recommendations will be based on the severity of the disease plus your dog's age, size, and overall health. In some cases, mild hip dysplasia can be conservatively managed with medical treatment alone. Surgery is often necessary in moderate to severe cases, however. Your vet may refer you to a veterinary surgeon for further evaluation and treatment.

Conservative Management

There is no medical cure for hip dysplasia. The goal of medical therapy is to ease the symptoms and slow the disease progression.

When hip dysplasia is mild to moderate, medical treatment and physical therapy can be very helpful.

• Nonsteroidal anti-inflammatory drugs, joint supplements, and/or disease-modifying osteoarthritis drugs may help give your dog some relief.
• Physical therapy helps many dogs build muscle mass, improve strength, and increase range of motion. 
• Regular low-impact exercise can also help your dog maintain muscle mass and decrease stiffness.
• If your dog is overweight, weight loss can significantly improve symptoms. Gentle exercise and diet change are essential for weight loss.

Surgery

There are several surgical options for the treatment of canine hip dysplasia. Your regular veterinarian will most likely refer you to a veterinary surgeon who is experienced with canine hip dysplasia. This surgeon will talk with you, examine your dog, and review the radiographs. In some cases, additional radiographs or other diagnostic tests will be recommended. Then, the surgeon will consider several factors, such as size, age, disease severity, and risk factors before determining the right course of treatment for your dog.

If surgery is recommended, one of the following surgical procedures will most likely be performed:

• Femoral Head Ostectomy: In this procedure, the femoral head is removed. For dogs weighing less than 70 pounds, this surgery can reduce pain and minimize the need for pain medications. However, it does not restore normal hip function. Plus, it is critical that the dog remain a healthy weight for the remainder of its life and only have limited exercise, such as leashed walks.
• Total Hip Replacement: As with humans, a total hip replacement in a dog involves the complete replacement of the ball and socket in the hip joint with implants. This surgery is done on young dogs who are not candidates for other types of surgery. Once healed, the dog generally has pain-free and normal range of motion in its hips.
• Pelvic Osteotomy: This surgery is done on puppies that have dysplasia but have not developed arthritic changes in the hip joint. It involves cutting the pelvic bone and rotating it to improve hip joint stability.
• Juvenile Pubic Symphysiodesis: This surgery is performed on puppies younger than 18 weeks of age who have joint laxity but no arthritic changes in the hip joint. It is a minimally invasive surgery that closes the growth plates in the puppy's pelvis. It alters the development of the pelvis to help prevent the laxity and degeneration that would occur should the bones grow normally. Most puppies are pain-free and have normal hip function within a few months of the surgery.
  

Your dog will need to recover after surgery so it can heal properly and regain the best function possible. Recovery time depends on the type of surgery done and your dog's individual rate of healing. Exercise restriction will be required, but your dog will also need to move the hips in a controlled manner. Physical therapy is an important part of the recovery process, whether you do it at home with instructions from your vet or you take your dog to a canine rehabilitation practitioner.

Talk to your veterinarian or veterinary surgeon about the expected risks, recovery times, success rates, and expense of the recommended options so you can make an informed decision. When in doubt, consider seeking a second opinion.

Prognosis for Dogs With Hip Dysplasia

With medical treatment or surgery, your dog should have a good quality of life with little pain and fairly normal range of motion in its hips. You will need to carefully maintain your dog's healthy weight, however, and possibly regularly give your dog pain medication if it has arthritic degeneration in the joint.

How to Prevent Hip Dysplasia

Because hip dysplasia is inherited and affected by a dog's development, you may not be able to prevent it from occurring in your dog. However, you can prevent the condition from getting worse by bringing your dog to the vet after the first signs of pain or lameness appear.

The occurrence of hip dysplasia may be minimized in purebred dogs through selective breeding. Dogs with hip dysplasia should not be bred. Reputable breeders of predisposed dog breeds will often have their dogs' hips screened and certified via the Orthopedic Foundation for Animals or PennHip prior to breeding them. Screening involves taking precisely positioned radiographs of the hips, usually done under sedation. Dogs can be certified after the age of two years. However, radiographs taken as early as four months of age may reveal a dog's susceptibility to hip dysplasia.