Hip Dysplasia in Cats

If you suspect your cat has hip dysplasia, watch for signs of lameness and demonstration of pain when you gently palpate the hip area. If you notice these signs, contact your veterinarian for an evaluation.

Hip dysplasia in cats is a genetically inherited malformation of the hip joint. When the ball and socket of the hip don't form properly, there is increased movement in the joint. The involved bones start to knock and rub against one another, leading to degeneration and a painful arthritis. A cat with hip dysplasia will show progressive signs of lameness like limping, unwillingness to move, continually chewing or licking the hip, and expressing pain when the hip area is touched.

The symptoms of hip dysplasia in your cat will vary depending on the amount of movement in the hip joint, and the extent of inflammation in the joint. Depending on the length and severity of the disease progression, you may notice:

• Reluctance to run, jump, or climb
• Difficulty rising
• Hind limb lameness that may be more pronounced after exercise
• Swaying or bunny-hopping when moving
• Standing with hind legs unusually close together
• Demonstration of pain in the hip joint - crying or resisting when area is touched
• Excessive licking or chewing in the hip area

As with dogs, hip dysplasia in cats arises from a combination of genetic and environmental factors. 

There is an inherited susceptibility in some cats for dysplasia. Although any cat can develop hip dysplasia, it is more common in the following breeds:

• Maine Coon
• Persian
• Himalayan

When a cat has genes that contribute to hip dysplasia, the ball and socket joint of the hip will be more shallow than normal, resulting in excessive movement of the bones in the joint.

If a cat has a shallow hip joint, the signs and severity of the disease will vary depending on the age and the following environmental and lifestyle factors:

• Weight gain or presence of obesity
• Nutritional level
• Muscle mass in the pelvic area

If your cat has been showing signs of lameness and pain in the hip, you should make an appointment with your veterinarian. The doctor will collect a detailed history from you. He or she will ask you about the symptoms you've been seeing and if there have been any recent events or injuries that may have led to the symptoms. Any information you have about your cat's parents may also help confirm a diagnosis.

Once the doctor has a history, he or she will conduct a thorough examination. Your vet will palpate the hips to check for loss of muscle mass and any demonstration of pain. The doctor will also manipulate affected hips to check for range of motion, signs of looseness in the hip, and any grating in the joint when it moves. Your cat's doctor may also run blood tests to check for signs of an inflammatory response. 

A definitive diagnosis can be made with x-rays of the hips. The pictures will help confirm a shallow hip socket and can reveal the severity of joint degeneration. X-rays will also serve to rule out other conditions such as an acute injury in the hip, spinal cord inflammation, or a bone disease.

With cats, the treatment options for hip dysplasia are fairly limited. Most measures will be non-surgical, but in advanced cases, surgery may be recommended.

Non-surgical Treatments

In most cases, hip dysplasia in cats can be treated with lifestyle changes. You will want to make sure your cat's diet encourages a healthy weight. Avoid overfeeding your animal, and encourage physical activity to maintain strong muscles in the hips. You can put your cat's food on a counter or table to encourage them to climb. You may also use some gentle passive moving of the hip joint to help decrease muscle stiffness.

If your cat is showing pain when moving, your veterinarian may choose to prescribe anti-inflammatory medication to help minimize swelling. Pain medications can also be given to make your animal more comfortable. To help strengthen the connective tissue in the joint, your veterinarian may recommend the dietary supplements glucosamine and chondroitin.

Surgical Options

In cases where cats are not responding to lifestyle changes and medication alone, surgery may be indicated. The two surgical options for adult cats with advanced hip dysplasia are a total hip replacement (THR) and an excision arthroplasty (EA). In the case of a THR, the hip joint is removed and replaced with an artificial ball and socket joint. Prognosis for most cats is good following a recovery period. With EA, the femoral head is removed, and nothing replaces it. The muscles in the hip will help the joint to function normally. As scar tissue builds in the area, there will no longer be bone-to-bone contact. Even if your cat has a slight limp due to the limb being a little shorter, there will be no pain. Following recovery, your cat should be able to engage in normal activity.

Hip dysplasia is a degenerative disease, so non-surgical treatments will last the duration of your cat's life. You can expect regular check-ups and blood work to monitor the progress of the disease and response to medication. If your veterinarian decides surgery is needed, there will be a recovery period involving restricted exercise and follow-up appointments for a few months.