Hip dysplasia is one of the most common skeletal diseases seen in dogs, but can affect cats and humans too. Large and giant dog breeds are most commonly affected.
Hip dysplasia is a disease of the hip where the ball and socket joints of the hip do not properly meet one another, resulting in a joint that rubs and grinds instead of sliding smoothly.
The Hip Joint
To better understand hip dysplasia we must have a basic understanding of the affected joint.
The hip forms the attachment of the hind leg to the body and is a ball and socket joint. The ball portion is the head of the femur while the socket (acetabulum) is located in the pelvis. To facilitate movement the bones are shaped to perfectly match each other, with the socket surrounding the ball.
To strengthen the joint, the two bones are held together by a strong ligament. The ligament attaches the femur head directly to the socket (acetabulum). The joint capsule, which is a very strong bond of connective tissue, encircles the two bones adding further stability.
The area where the bones actually touch each other is called the articular surface. It is perfectly smooth and cushioned with a layer of spongy cartilage. The joint also contains a highly viscous fluid that lubricates the articular surface.
In a normal hip joint all these factors work together to allow the joint to function smoothly and with stability.
Dysplastic Hip Joint
In a dysplastic hip joint the femur head and/or socket are malformed and do not meet up with each other, causing the hip to partially dislocate. Wear and tear of the deformed joint results in varying degrees of inflammation and degeneration.
What Causes Hip Dysplasia
The development and progression of hip dysplasia is influenced by hereditary and environmental factors.
“Hereditary” relates to the generic code that is passed on to the offspring by both parents, whereas “environmental” refers to all the outside influences which alter and shape the growth and function of the bones, cartilage, ligaments, tendons and muscles.
The most common environmental influences are:
- Joint laxity due to traumatic injury, overloading of the joint by weight or lack of muscle strength.
- Rapid weight gain and obesity, putting excessive strain on the joints.
- Incorrect/poor nutrition during the growth stages.
- Too much or incorrect exercise during the growth stages.
Symptoms
The symptoms of hip dysplasia depends on the degree of joint looseness or laxity, joint inflammation and the duration of the disease and seem similar to the signs of arthritis.
Symptoms include:
- Decreased activity
- Difficulty rising
- Reluctance to run, jump or climb stairs
- Painful joints
- General stiffness
- Intermittent or persistent hind-limb lameness (especially after exercise)
- “Bunny-hopping” or swaying gait
- Audible clicking or grating sound coming from the hips while walking
- Narrow stance in the hind limbs
- Decreased range of motion in the hip joint
- Loss of muscle mass in the thigh muscles (muscle atrophy)
- Enlargement of the shoulder muscles due to more weight being exerted on the front legs as the dog tries to avoid weight on its hips
Diagnosis
Recognising symptoms early is important and your vet can help you with this.
Your vet will perform a thorough physical examination and perform some manual tests on your dog’s hips and legs. It is also very important to give the vet a thorough history of your dog’s health, onset of symptoms and any possible incidents or injuries that may have contributed to the symptoms. Your vet will also need to take x-rays to determine the degree of dysplasia and arthritis.
Treatment
Hip dysplasia can be treated medically and surgically.
Because hip dysplasia is primarily an inherited condition, there are no products on the market that can prevent its developments. Through proper diet, weight management, exercise, oral supplements, anti-inflammatories and pain relief, you may be able to decrease the progression of osteoarthritis, but the looseness in the joint or bony changes will not change significantly.
Managing your dog’s weight is very important. Excess weight causes additional strain on the already affected joint(s).
Exercise should fit to the individual dog’s maximum intensity level with the goal to maintain muscle tone and cardiovascular function without causing pain, stiffness and inflammation to the joins(s).
Your vet may recommend a special diet such as Hill’s J/D, Hill’s Metabolic + J/D, Royal Canin Mobility or adding an oral supplement to your dog’s diet, e.g. GCS Advanced Joint Care, GlucoCARE Advanced Joint Support or Mobiflex.
Your vet may also prescribe your dog anti-inflammatory pain medication to help with pain management.
Physical therapy may also be recommended.
There are several surgical procedures available to treat hip dysplasia, depending on the dog’s age, body size and the severity of the hip joint’s degeneration.
- Triple Pelvic Osteotomy – Involves surgically breaking the pelvic bones and realigning the femur head and socket (acetabulum) restoring the weight-bearing surface area and correcting the femur head subluxation. This procedure is performed on dog’s younger than 10 months of age with severe hip laxity, but no developed damage to the joints.
- Juvenile Pubic Symphysiodesis – This surgery primarily fuses two pelvic bones together, allowing the other pelvic bones to develop normally. This changes the angle of the hips and improves articulation of the joints, lessening the likelihood of osteoarthritis. This procedure must be done before 20 weeks of age and before any signs of arthritis are evident.
- Total Hip Replacement – Involves the removal of the existing joint and replacing it with an artificial joint prosthesis. This procedure can only be performed on dogs that are skeletally mature.
- Femoral Head Excision – Is a procedure in which the femur head is surgically removed and fibrous pseudo-joint replaces the hip naturally. This procedure is performed in cases where degenerative joint disease has occurred and a total replacement is not feasible.
With the right treatment and management, hip dysplasia can often be managed successfully and allow for a healthy, happy life for your dog.
