Hip Dysplasia in Dogs: Causes, Signs and What Helps

Hip dysplasia is an abnormal development of the hip joint, where the ball and socket do not fit together properly. The looseness causes abnormal wear, which causes osteoarthritis, which causes pain.

It is one of the most common orthopaedic conditions in dogs, and it is partly preventable.

What goes wrong

A normal hip is a deep socket holding a well-fitting femoral head. In a dysplastic hip, the socket is shallow, or the ligaments are lax, or both. The joint subluxates — slides partially out — with every step.

The body responds with inflammation, then with new bone formation, then with cartilage loss. By the time a dog is middle-aged the joint is arthritic.

Importantly, the severity of the changes on an X-ray correlates poorly with how much pain a dog is in. Some dogs with dreadful hips cope well; some with mild changes are very lame.

Causes

Genetics is the largest factor. It is polygenic — many genes contribute — which is why it has been so hard to breed out.

Growth rate. Puppies grown too fast, on too many calories, develop the condition more often.

Nutrition. Excess calcium during growth is directly implicated. This is why large-breed puppies need a diet formulated for large-breed growth, with controlled calcium — and why adding a calcium supplement to a complete puppy food is actively harmful.

Body weight. Both during growth and for life. The Labrador lifetime study found dogs kept lean had significantly less hip arthritis and developed it later.

Exercise during growth. Repeated high-impact activity before the growth plates close — long road walks, jogging alongside, stairs, jumping from heights — is associated with higher risk. Free play on grass is not.

Neutering age. Research from UC Davis has found associations between early neutering in some large breeds and increased rates of joint disorders including hip dysplasia, plausibly because sex hormones signal growth plate closure.

Which breeds

Most common in large and giant breeds: German Shepherds, Labradors, Golden Retrievers, Rottweilers, Newfoundlands, Saint Bernards, Bernese Mountain Dogs, Mastiffs, Old English Sheepdogs.

It also occurs in smaller breeds, including Pugs and French Bulldogs, where it is under-recognised.

Signs

In young dogs (5 to 12 months):

• Bunny-hopping — using both back legs together when running
• Reluctance to go up stairs or jump
• A swaying or wobbling gait at the back end
• Difficulty rising after rest
• A clicking sound from the hips
• Reduced activity, or lying down during walks
• Narrow stance at the back

In older dogs:

• Stiffness after rest, easing with movement
• Loss of muscle over the hindquarters, so the back end looks narrow and the shoulders look overdeveloped
• Difficulty rising, especially on slippery floors
• Reluctance to exercise
• Shifting weight forwards
• Behaviour changes — grumpiness, less play, more sleeping

Diagnosis

Physical examination, including specific tests for joint laxity, followed by X-rays under sedation. Sedation matters: the positioning required is not achievable in a conscious dog and the images are useless without it.

Several formal scoring schemes exist for breeding purposes, and PennHIP measures laxity specifically and can be performed from four months.

Treatment

Conservative management, which is what most dogs receive and what works well for many:

• Weight control. The single most effective intervention. A lean dog with bad hips does dramatically better than a heavy one with the same hips
• Controlled exercise — little and often, on soft even ground. Swimming and hydrotherapy are excellent, being non-weight-bearing while building the muscle that stabilises the joint
• Pain relief. Veterinary NSAIDs, and newer monoclonal antibody injections. Do not use human painkillers
• Physiotherapy, which is underused and genuinely valuable
• Omega-3 fatty acids at an appropriate dose, which have the best evidence of any supplement
• Environment — non-slip flooring, ramps, a firm orthopaedic bed, warmth

Surgery, for dogs not managed adequately with the above:

• Total hip replacement — the gold standard for severe cases. Expensive, highly effective, usually restoring near-normal function
• Femoral head and neck excision (FHO) — removing the femoral head so a false joint forms from fibrous tissue. Works well in smaller and lighter dogs
• Juvenile pubic symphysiodesis (JPS) — a preventive procedure in very young puppies, requiring early diagnosis before about 20 weeks
• Triple or double pelvic osteotomy — reshaping the pelvis in young dogs with laxity but no arthritis yet

What you can influence

You cannot change your dog’s genes. You can change:

1. Keep them lean, for life. This is the biggest lever you have
2. Feed a large-breed puppy formula if they will mature over about 25kg, and never add calcium
3. Do not grow them fast. A lean puppy reaches the same adult size, more safely
4. Limit high-impact exercise during growth — no road running, no stairs repetitively, no jumping out of cars
5. Discuss neutering timing with your vet rather than defaulting to six months
6. Build and maintain muscle through appropriate exercise
7. Non-slip flooring, which prevents the slips that damage already-unstable joints

Buying a puppy

If you are choosing a large-breed puppy, ask to see hip scores for both parents from a recognised scheme, and compare them with the breed average.

A breeder who cannot produce them, or who says the dogs “have never had a problem”, is not screening. Screening is not a guarantee — the condition is polygenic and even well-scored parents can produce affected puppies — but it shifts the odds substantially, and it is the single most useful question you can ask.