Hip dysplasia in dogs

Hip dysplasia is probably the most commonly occurring skeletal problem that dogs can suffer from. If you have a dog already or are considering getting a new puppy or adult dog, it's worth finding out a little bit about the condition for your own peace of mind and so that you can be aware of any potential problems.

What dogs suffer from hip dysplasia?

Hip dysplasia develops due to a combination of genetically inherited traits and external environmental factors. Hip dysplasia means that the hip joints don't develop properly, leading to a degree of malformation that varies from dog to dog. It generally begins to develop while the dog is still young, and leads to a gradual deterioration of the joins and associated loss of full functionality. Both dogs and bitches are equally likely to be affected, and any breed or type of dog can possibly suffer from the condition - however it is more prevalent in large breeds of dog such as the Labrador, German shepherd, Bulldog, Saint Bernard and Great Dane. Dogs which are known to have hip dysplasia or a genetic predisposition to it should not be bred from.

Hip dysplasia in detail

The hips of the dog consist of the ball and socket joint that attaches the hind legs to the rest of the skeleton. The head of the femur makes up the ball, and the acetabulum socket is part of the pelvis. The ball and the socket should be perfectly shaped to fit each other, with the ball able to rotate comfortably but securely within the socket. The two bones are held in place with ligament and connecting tissue, and the joint contains lubricating fluid that facilitates smooth movement of the ball and socket. Hip dysplasia occurs when the joints develop abnormally, without a comfortable fit between the ball and the socket, and associated looseness of the surrounding muscle, connecting tissue and ligaments occur. As the condition progresses, the surfaces of the ball and socket joints begin to lose contact with each other and the bones begin to separate. This is known as subluxation. Even dogs that go on to suffer from hip dysplasia as they develop are usually born with normal hips, which is why hip score testing (described below) is usually performed on the parents of a puppy to identify a genetic predisposition, rather than on the puppy itself. The subluxation leads to malformed development of the joints of the hips, and the associated pain and altered gait. Hip dysplasia may affect only one side of the hips, or both- both hips being affected is referred to as a bilateral hip dysplasia.

Identifying hip dysplasia

If you own or are considering getting a breed of dog that is thought to be at a higher risk than average of developing hip dysplasia, then you might want to consider asking for hip scores to be taken for the dog or its parents. This involves x-rays being taken of various angles of the dog's hips, and examination of the findings. The dog is then scored accordingly, with the lowest score being the best result in terms of identification of any present or developing problems. The following signs and symptoms may also be indicative of a dog with hip dysplasia.

• Lameness in the rear legs, often appearing after exercise
• Short, choppy stride from the back legs due to pain when fully extending the legs
• Swaying movement of the rump when walking or running
• The dog tilting its hips downwards when pushed on the rump
• Stiffness or awkwardness in climbing or getting up and down
• A hopping gait when running, with the two back legs moving together
• Overuse of the front legs, with the back legs dragging
• A waddling gait in the back legs

Treating and managing hip dysplasia

There are a variety of surgical and medical treatment and management options for dealing with a dog with hip dysplasia, which are intended to halt further deterioration of the joints and decrease any associated pain. Hip dysplasia cannot be corrected or cured through medication alone, and surgical options may not be appropriate or financially viable for all animals. Which manner of treatment is relevant and appropriate for the animal in question depends on a variety of factors, including the age of the dog, the degree of development of the dysplasia, exacerbating environmental factors, and the ongoing cost of managing the condition.

Painkillers and anti inflammatory medications

Painkillers (analgesics) and non steroidal anti inflammatory medications are often prescribed in the short term in able to encourage the dog to become more active, which in itself can improve the symptoms of the condition. These medications act as painkillers rather than as a treatment or ultimate solution, as they only mask the symptoms rather than providing a cure.

Diet and exercise

Dogs which maintain a healthy weight and are kept as active as possible (within the confines of any discomfort or pain caused by the condition) are likely to suffer from less pain and a reduced severity in symptoms than an overweight, sedentary dog. If your dog is diagnosed with hip dysplasia, addressing their physical condition and diet and exercise needs is normally the first thing you will need to do.

Surgical options

There are four main surgical options that may be considered for a dog suffering from hip dysplasia- A total hip replacement, a triple pelvic osteotomy, a femoral head osteotomy, or a darthroplasty.

• In a total hip replacement, the affected ball and socket joint (possibly on both sides in the case of a bilateral hip dysplasia) are completely replaced with an artificial ball and socket, in a similar way to the way hip replacement surgery is performed on people. This procedure is a very specialist and difficult surgery, and only a few referral centres and specialist veterinarians are equipped and competent to perform the procedure.
• In a triple pelvic osteotomy, the hip bones are cut in three separate places so that the socket can be adjusted in order to allow a better fit with the ball part of the joint. The joint is then held in place by metal plates and screws.
• In a femoral head osteotomy, the malformed or damaged ball part of the joint is removed, and the part of the femur that remains then forms a false joint with the ligaments and muscles in the hips. While the dog will never recover the full range of movement and formation of healthy hips, this surgery does generally lead to a marked improvement in the condition and much less pain.
• Darthroplasty involves a 'shelf' of bone being made on the edges of the joint socket, which then fuses into position and stops the free movement of the poorly fitting ball part of the joint from slipping in and out of the socket. This surgery is a relatively new development, and is generally performed in younger dogs.