Hip dysplasia

What is hip dysplasia?

Hip dysplasia is a congenital condition where the 'ball' of the femur (thigh bone) does not fit into the 'socket' in the pelvis. It is more common in purebred dogs, particularly large breeds such as Labrador, Golden Retriever and German Shepherd. If not corrected early, abnormal pressure in the joint will lead to early development of osteoarthritis.

How do I know if my dog has hip dysplasia?

Dogs with moderate to severe hip dysplasia will often show signs at 4 – 12 months of age, including:

• Lameness of one or both hindlimbs
• A 'bunny-hopping' gait
• Difficulty getting up, climbing stairs or running
• Pain on manipulation of the hips

Dogs with milder hip dysplasia may not show any signs until they start to develop osteoarthritis in the hips.

Dogs with hip dysplasia should not be bred, as there is a strong genetic component to the disease.

How is hip dysplasia diagnosed?

If we suspect hip dysplasia, we will probably recommend a general anaesthetic to examine the hips more closely for laxity (looseness) and take x-rays to determine exactly how loose the hips are. This will help us form a treatment plan. Some people elect to have x-rays of the hips taken even in the absence of clinical signs if their dog is an at-risk breed.

What are the treatment options for hip dysplasia?

The treatment options for hip dysplasia depend on the age, size and activity level of the dog, the clinical signs, the presence or absence of secondary osteoarthritis in the hips, expense and owner preference. If your dog has evidence of hip dysplasia but is not showing any clinical signs, we usually recommend no treatment. If your dog is young, showing signs of hip dysplasia and has no evidence of osteoarthritis, the treatment of choice is Triple Pelvic Osteotomy (TPO) (see below). If there are signs of osteoarthritis, TPO is no longer an option and we will need to either manage the case conservatively or consider Total Hip Replacement (THR). The treatment options are discussed here:

Triple Pelvic Osteotomy (TPO)

TPO is a technique that aims to change the anatomy of the hip joint so that the 'ball' fits perfectly into the 'socket'. This involves cutting the pelvis in three places then rotating that part of the pelvis so that the 'socket' part of the joint fits over the 'ball' part of the joint properly. This procedure requires referral to a specialist surgeon.

Conservative management

If TPO is not an option for any reason, we will generally recommend conservative treatment to start with. There are several aspects to this approach:

• Diet: It is important to maintain a healthy weight to minimise pressure on the joints.
• Exercise: Frequent or high-impact exercise can speed up the progression of osteoarthritis. You should limit off-leash exercise and establish a suitable distance for walks. Start with 20 minute walks and gradually increase the distance you cover. When your dog starts to become lame or tired, you will know you have passed the threshold of how much exercise he or she can handle. Swimming is a great form of exercise, as it uses the muscles without stressing the joints.
• Joint supplements: Adding glucosamine, chondroitin and/or fish oil to the diet helps slow the progression of osteoarthritis by maintaining the cartilage inside the joint and providing a natural anti-inflammatory effect.
• Pentosan polysulphate: This is a series of four weekly injections followed by three-monthly booster shots. It works in a similar way to glucosamine and chondroitin, by maintaining cartilage health and increasing joint fluid to cushion the joint.
• Pain relief: We may prescribe an anti-inflammatory medication for your dog to help alleviate pain – similar to Nurofen in people (but not the same – do not give your dog Nurofen!). If this is still not enough, there are additional pain relief medications we can try.

Total Hip Replacement (THR)

If osteoarthritis in the hip joint is causing considerable pain and is not responding to conservative therapy, we may recommend a total hip replacement. This involves replacing the head of the femur (the 'ball') with a metal implant, and inserting another implant in the 'socket' of the joint. This means that motion of the joint will be smooth and painless again. Recovery from this procedure generally takes about 6 – 12 weeks. This procedure requires referral to a specialist surgeon.

Femoral Head and Neck Excision (FHNE)

In small dogs with unacceptable hip pain, total hip replacement is still the treatment of choice. However, if this procedure is not possible for financial reasons, FHNE (also known as femoral head ostectomy [FHO]) is another option. This involves removing the head of the femur (the 'ball') so that there is no longer painful contact between the 'ball' and the 'socket' of the joint. Your dog will probably still be lame because there is no longer a functional joint in the leg, but this will be a 'functional lameness' – meaning that it is caused by an abnormality in the structure of the limb, rather than because the limb is painful.