Hip Dysplasia

Hip Dysplasia is a developmental disease of the hip joint seen in most breeds of dogs and in some cats. Lameness and exercise intolerance are the most common clinical signs. Hip dysplasia is treated with rest, restricted activity, pain medication, and, in severe cases, surgery. This information will help you learn more about hip dysplasia and will review your veterinarian's instructions for your pet's care at home.

The hip joint is formed from the pelvis, which serves as a socket, and the top of the femur (thighbone), which has a rounded end that fits into the socket. Cartilage lines the surfaces of the bones that make up the socket. Membranes called a capsule surround the joint and contain fluid that lubricates the joint surfaces. In normal dogs and cats, the head, or top, of the femur fits snugly within the socket on the pelvis.

Dogs and cats with hip dysplasia may have normal hip joints at birth; however, their joints subsequently undergo changes that are characteristic of hip dysplasia. In younger patients, hip dysplasia is seen as a dislocation or partial dislocation of the head of the femur. Dislocation produces joint laxity and stretches the joint capsule, causing pain and lameness. Tiny fractures of the pelvis also contribute to this syndrome. In older pets (about two years old and older), the changes seen include cartilage erosion in the joints, flattening of the femoral head, and arthritis.

Causes

The causes of hip dysplasia are complex and involve heredity, trauma and environmental factors such as overeating and rapid weight gain.

Diagnosis

Your veterinarian will confirm the diagnosis by palpating (examining by touching) the hip joints and by taking x-rays. Anesthesia may be required to obtain diagnostic x-rays.

Treatment and Home Care

Treatment for hip dysplasia is based on the age and size of the patient, the degree of pain, physical examination and x-ray findings, and your expectations of how active your pet should be.
Conservative treatment benefits many patients when they experience signs of hip dysplasia. This treatment includes enforced rest, anti-inflammatory drugs, and pain medication. Once the clinical signs are controlled, the therapy includes weight reduction and an exercise program designed to improve the strength of your pet's rear legs. Such an exercise program might include swimming and walking uphill.
Surgery may be performed to lessen the signs in some pets. Surgical procedures reorient the bones making up the hip joint or, in some cases, remove the affected bones that cause the problem (e.g. total hip joint replacement). Because animals with hip dysplasia should not be bred, your veterinarian may recommend castration or ovariohysterectomy (spaying) for your pet.
Home care consists of carefully following your veterinarian's instructions for giving medications, enforcing rest, and exercising your pet. If your pet has had surgery, you will need to check the incision at least once a day for swelling, discharges, and missing sutures. If any of these occur, or if your pet loses its appetite, see your veterinarian at once.

Dietary Plan

If your pet has hip dysplasia, your veterinarian may give you special feeding instructions based on your pet's age (young vs. middle-aged to older) and body condition (overweight). If your pet is a young adult your veterinarian may prescribe a pet food that supplies nutrients for proper development and tissue repair. Optimal nutrition should also reduce the health risks associated with feeding excess nutrients such as calcium and phosphorous, which could cause skeletal problems, and excess calories, which could lead to obesity and complicate signs of hip dysplasia.
If your pet is overweight, your veterinarian may prescribe a special food to help return your pet to its optimal weight, which helps reduce stress on the hip joints and helps prevent the progression of arthritis. Once your pet's weight returns to normal, you veterinarian may recommend a reduced-calorie, increased-fiber food to help manage the long-term risks of excess weight gain.