Hip Dysplasia

Dr Gemma Gaitskell (BVetMed MSc MRCVS, Royal Veterinary College, London)

 

Hip dysplasia in dogs is a multifactorial developmental orthopaedic disease that affects the hip joint. It is an inherited condition but there are also environmental factors that can influence its development.

Large dogs and some breeds are more likely to be affected. Hip dysplasia eventually leads to changes in the joint which cause osteoarthritis leading to pain and discomfort for the dog.

What is Hip Dysplasia?

Model of Hip Dysplasia in Dogs

Hip dysplasia in dogs is an orthopaedic problem in the hip or coxofemoral joint which is caused by abnormal development and growth. These abnormalities cause the hip joint to become unstable and lax due to a discrepancy between the way the bones and muscle around the joint are growing. 

Ultimately, this means the different parts of the joint do not fit together as they should, leading to damage to the inner surfaces of the joint every time the dog moves. Over time, this damage can become considerable. These primary developmental changes can then cause secondary problems such as osteoarthritis caused by the abnormal wear and tear on the joint.

Either one or both hip joints can be affected. Eventually, the secondary changes cause pain, this can lead to lameness and an unwillingness to move and exercise, which often results in weight gain, thus exacerbating the problem further and creating a downwards spiral effect.

How do Dogs Get Hip Dysplasia?

Unlike people, most dogs are not born with signs of hip dysplasia. However, abnormal development and growth becomes magnified over time, particularly around 3 to 9 months of age when growth is at it’s fastest. These abnormalities begin to develop when puppies’ activity levels increase.

Although hip dysplasia is inherited environmental factors, such as inappropriate nutrition, incorrect levels of exercise, the presence of other skeletal disorders, weight and growth rate can also play a major role in the development of the condition. It is therefore called a multifactorial disease.

When Are Dogs Most at Risk from Hip Dysplasia?

Hip dysplasia is most common in large dogs and pure bred dogs are more likely to be affected than cross-breeds. Obesity can also increase the level of stress on joints and exacerbate any signs if they are present. Too much exercise for large breed dogs as puppies can also contribute to the development of hip dysplasia.

Which Breeds Are Most Commonly Affected by Hip Dysplasia?

Newfoundland

Hip dysplasia is a common problem in dogs and many different types and breeds of dog can be affected, but some breeds are more likely to suffer from the condition than others.

Some of the breeds that have the highest occurrence of hip dysplasia include:

• Bernese Mountain Dog
• German Shepherd
• Golden Retriever
• Labrador Retriever
• Newfoundland
• Rottweiler

Symptoms of Hip Dysplasia in Dogs

The symptoms of hip dysplasia in dogs can vary greatly and are not always in line with the radiographic changes seen on x-rays. Some symptoms of hip dysplasia can include:

• Hindlimb stiffness
• Difficulty getting up from a resting position
• Some young dogs can appear to be swaying as they walk

Hip dysplasia may not be immediately obvious in many young dogs and it is only when the secondary changes caused by the initial dysplasia start to become apparent at an older age that owners realise their dog is affected:

• The level of lameness which a dog displays can range from mild to severe usually becoming more obvious after exercise
• Dogs can display a gait, which resembles a bunny hopping
• A reduced range of movement in the hip joint compared to a healthy dog

Diagnosis of Hip Dysplasia in Dogs

Hip dysplasia in dogs is usually diagnosed using a combination of clinical signs and radiography. The instability in the joint can often also be felt by a veterinarian who knows what to look for, whilst carefully examining the dog. X-rays are useful for evaluating how much damage there is to the joint and the degree of arthritis present. Together with the clinical signs this allows a decision to be taken on the most appropriate treatment options for the dog in question.

Can Hip Dysplasia in Dogs Be Treated?

There are different types of treatments available to alleviate the symptoms of hip dysplasia in dogs depending on its severity. These treatments include both medical and surgical options. Some common treatment options include:

• Weight reduction
• Physiotherapy under expert supervision to help strengthen muscles
• Reducing the amount of exercise on hard surfaces
• Anti-inflammatory medication
• Joint supplements
• Surgical options which range from various procedures to reduce pain and arthritis through to complete hip replacement

The prognosis for dogs suffering from hip dysplasia can be extremely variable and is dependent on many different factors. Surgery generally has a beneficial outcome when used appropriately. However, for dogs where surgery is not an option due to other health problems or financial constraints treatment should be focused on management and lifestyle changes to improve the dogs quality of life.

Preventing Hip Dysplasia in Dogs

As hip dysplasia is an inherited condition, there are health schemes which aim to control the prevalence of the condition. Breeders are encouraged to participate in these schemes. Dogs which are intended for breeding should have x-rays of their hips performed by a veterinarian who will then send them to be scored independently by experts. In the United Kingdom, the British Veterinary Association (BVA) is responsible for the hip dysplasia scheme.

Dogs should be at least a year old before they have their hips scored. Each dog which is evaluated and radiographs of their hips, are assigned a score which combines both hips using a number of standardised criteria. The lower the score the fewer the signs of hip dysplasia are present. Each dog is then given a certificate with its score. Ideally, breeders should only breed from dogs that have a score lower than the median score assigned to the breed in question with the long term aim of reducing the prevalence of hip dysplasia.

If you are thinking of getting a pure-bred puppy you should investigate whether the breeder has had the parents hip-scored. Responsible breeders will have had their dogs evaluated and should be trying to breed in a way that minimises the prevalence of hip dysplasia in a breed as much as possible. Careful selection of a puppy by informing yourself about its family history is the best way of avoiding having to deal with the sometimes devastating effects that hip dysplasia can have later in life. Despite this, even puppies with parents with a low hip score can still be affected.

It is also important to try and minimise the environmental factors that can contribute to the condition. This means ensuring that your dog is fed an appropriate diet and does not become overweight, as well as tailoring exercise to a level that is appropriate for the age and breed of dog.

The Importance of Responsible Breeding

Responsible breeding and selection of puppies from breeders using parents and grandparents with low hip scores plays a vital role in reducing the incidence of hip dysplasia in the pure-bred dog population. This is important as by doing so dogs welfare can be improved as ultimately hip dysplasia can be a painful condition which affects a dogs quality of life.