Most dog owners are familiar with canine dip dysplasia.
Some of you probably know more than they ever wanted to know. In dogs, hip dysplasia can be a devastating, debilitating, and expensive disability.
Unfortunately, cats can suffer from hip dysplasia, too, although most cat owners have never heard of it.
Define the Parts
Before we talk about hip dysplasia itself, let's define the parts of the hip affected by this disorder. The femur (the large, upper thigh bone) has a large knob (or ball) at the top end. This knob, also called the femoral head, is where the femur interacts with the hip.
To aid this interaction and to allow the femur to move freely, the hip has a socket. This cup shaped shallow depression on each side of the hip is also called the acetabulum. When all is well, the femoral head fits snugly and so perfectly that the ball moves smoothly and freely within the socket. The movement is aided by cartilage in the joint.
What Is Hip Dysplasia?
Hip dysplasia is a deformity of the femoral head and/or the hip socket. There are varying degrees of hip dysplasia, from mild to severe, depending on the changes seen in the joint.
The head of the femur may be less than round, ranging from a slight flatness (just out of round) to an enlongated, flattened knob. The socket in the hip may be shallow; allowing the head of the femur to move too much.
When the ball and socket don't fit together correctly, the ball will move too much and eventually the socket will wear down and become even looser. As the two bones move roughly against each other (instead of gliding) the cartilage can become damaged and movement will be painful. Over time arthritis will develop; causing even more pain.
The causes of hip dysplasia in dogs is still a hotly debated topic, especially when trying to determine why certain dogs develop it and others do not. Many experts feel there are multiple ways for it to occur, including genetics, early puppy development, weight during puppyhood and early adulthood, too much exercise, or too much activity that stresses the hips in puppyhood. In other words, for all the research, hip dysplasia is not yet fully understood.
It is even less understood in cats. Some of this is because cats, as much smaller animals, seem to avoid some of the physical stresses that is thought to lead to the deformities in dogs. Cats also protect themselves better than dogs. For example, cats will rarely play and exercise to the point that they hurt themselves as dogs sometimes do.
However, there is thought to be a genetic component to the disease in cats as there is in dogs. The larger and heavier breeds, including Persians and Maine Coon cats, seem to have a higher incidence of hip dysplasia than smaller, lighter weight breeds or mixed breeds.
Obesity seems to be an environmental cause of hip dysplasia in dogs. Although with felines it's not known if the obesity causes hip dysplasia only in cats predisposed to it or not. After all, not all obese cats have hip dysplasia, although quite a few dysplastic cats are overweight.
If your veterinarian suspects hip dysplasia, it can be diagnosed by x-raying the hips and femoral heads.
Signs of Hip Dysplasia
One of the first signs of hip dysplasia in cats is stiffness. When getting up from sleep or a nap, the cat may be hesitant to move and probably won't stretch as most cats do upon awakening. The cat may protect her hips, keeping them tucked or sitting more than normal. Her gait may be odd; she may run with both back legs together (bunny hopping). Cats with significant deformity in the hips or arthritis won't want to play and in fact will often avoid physical activity. Some cats will cry (or even bite) if their hips are manipulated by the veterinarian.
Your Cat is Dysplastic, What Now?
Most experts stress that controlling your cat's weight is important, but your cat shouldn't be skeletal; muscle mass is vital to keep her strong while excess weight will stress those hip joints. Talk to your veterinarian about your cat's food, feeding sizes, and a goal weight. In addition, your veterinarian will also provide guidelines for weight loss goals as the process must be slow.
Exercise is also important as keeping your cat's body strong will help her cope with hip dysplasia. Many dysplastic cats tend look like they are front wheel drive cats as often the shoulders and chest muscles will get stronger and larger to take over for the weak hip muscles. If your cat is sore and unwilling to move, begin her exercise by simply asking her to walk. For example, with her breakfast in hand, simply ask her to walk a few feet to you and then reward her with a bite of her foot. Gradually ask her to walk more and more.
Glucosamine and chondroitin are often recommended for cats as they are for dogs. These can aid in maintaining the connective tissues in the joints. Ask your veterinarian if these could benefit your cat and if so, what dosage would be appropriate.
If your cat looks uncomfortable, or maybe in pain, your vet may recommend anti-inflammatory or pain medications. It's important, however, to not give your cat over the counter anti-inflammatory medications as some are toxic and will kill your cat. Use these and pain medications only as prescribed by your veterinarian.
Currently, the surgeries for hip dysplasia used for dogs are not commonly used for cats. This may change in the future, however, so if your cat does have hip dysplasia, keep the lines of communication open with your vet.