Hip Dysplasia in Dogs

Hip dysplasia refers to the malformation of the ball and socket of one or both hip joints. The malformation causes the head of the femur to rub and grind in the joint socket instead of gliding smoothly and securely. The disorder is inherited through a number of genes and can result from inheritance, environmental factors, or a combination of both. The onset of dog hip problems can occur at any age and results in pain, restricted movement and loss of hip function. Hip dysplasia is an inherited condition resulting from an improperly formed hip joint. Because the joint is loose, the dog's leg bone moves around too much, causing painful wear and tear. A physical exam will check for painful joints and reveal whether the pet has correct range of motion in the hip joints.

Signs of hip dysplasia in dogs may or may not be present and depend on degree of joint inflammation, joint looseness, and disease duration.

• Decreased activity
• Hind limb lameness
• Difficulty getting up
• Difficulty jumping or climbing stairs
• Bunny hopping
• Decreased range of hip motion
• Narrow hind limb stance
• Loss of hind limb muscle mass
• Painful hip joints

Early onset hip dysplasia can develop as early as 16 weeks of age. Later onset or geriatric dysplasia is often caused by osteoarthritis or joint cartilage degeneration. One or both joints may be affected. Causes of hip dysplasia can include:

• Rapid weight gain
• Obesity
• Injury
• Malnutrition

Genetic susceptibility can play a role. Both large and small breeds can be affected, although large breeds are more prone. For example:

• Hip dysplasia is common in Pit Bulls as are knee problems like torn CCLs and ACLs
• Hip dysplasia in Boxers typically results from genetics, but obesity can be another determining factor
• Obesity and over-exercising when young can lead to hip dysplasia in Bulldogs
• Many working breeds love to play hard at any age and strenuous activity, along with genetics, can lead to hip dysplasia in Rottweilers
• A large percentage of Golden Retrievers have hip dysplasia due to genetics so prospective parents should be screened before being bred

If you suspect your pet is showing signs of hip dysplasia or if you wish to have your pet examined for the condition, the veterinarian will gather a history of symptoms, onset, and any past injuries. Genetic parentage information for your pet can also be helpful in diagnosing hip dysplasia. A physical exam will check for painful joints and reveal whether your pet has correct range of motion in the hip joints.

Radiographs provide the definitive diagnosis for hip dysplasia, allowing the vet to visualize shallow hip sockets and/or malformed femoral head. To obtain a breeding certificate, many breeds must undergo a series of radiographs to rule out hip dysplasia. There are currently two methods, OFA and PennHip, for detecting hip dysplasia for breeding purposes.

OFA

The Orthopedic Foundation for Animals (OFA) has outlined a protocol to test for hip dysplasia in breeding dogs. The pet must be at least 2 years of age at the time radiographs are taken. The veterinarian provides x-rays that are then sent to the OFA for scoring. Anesthesia is recommended to get accurate radiographs. X-rays are reviewed by a panel of radiologists and a score is assigned based on breed and age. Hips are graded excellent, good, fair, borderline, mild, moderate or severe. Dogs with hips that score at borderline or lower cannot be assigned an OFA breeding number.

PennHip

This protocol comes from the University of Pennsylvania Hip Improvement Program. Radiographs are taken under heavy sedation and dogs as young as 16 weeks can be measured. Hips with a distraction index of greater than 0.3 are labelled degenerative joint disease susceptible.

Diet and Weight Management

Proper nutrition and weight maintenance can be first and foremost as methods of treatment for hip dysplasia in dogs. Monitoring the progression of hip dysplasia is important so that preventative measures can be taken. Large and fast-growing breeds should be fed a proper diet to prevent joint degeneration and have a low impact exercise program to strengthen muscles around joints. The veterinarian will have weight management and exercise recommendations for your pet’s age, breed and degree of hip dysplasia.

Oral supplements

Glucosamine and chondroitin supplements are safe and can aid in joint maintenance for osteoarthritis patients. They supply the building blocks needed to generate joint cartilage and inhibit damaging enzymes. Supplements may take up to 6 weeks to show effects.

Physiotherapy

Physiotherapy provides low impact physical therapy to help loosen joints and develop muscle mass. Swimming is a good form of low impact physical therapy for hip dysplasia patients.

NSAIDS

Non-steroidal anti-inflammatory drugs (NSAIDS) relieve pain and reduce inflammation. They are not recommended for long-term use and liver function should be monitored every 6-12 months when using these medications.

Surgery

Hip dysplasia surgery in dogs may be recommended for pets depending on age, size, activity level, degree of laxity and degree of degeneration.

• Triple pelvic osteotomy (TPO) – Performed at less than 10 months old for pets with severe joint looseness but no joint damage. Breaks pelvic bone and realigns the hip joint.
• Total hip replacement – Performed on pets with degenerative joint disease from chronic hip dysplasia. The hip joint is removed and replaced with an implant.
• Excision arthroplasty – Performed only on pets less than 40 pounds. Head of the femur is removed and replaced with an implant. For degenerative joint disease patients and significantly less costly than total hip replacement.
• Juvenile pubic symphysiodesis – Performed before 20 weeks of age, prior to symptoms of hip problems. Pelvic bones are fused together, changing the angle of the hips and lessening the chances of developing osteoarthritis.

Selective breeding and proper nutrition and exercise are the best methods of preventing hip dysplasia. Diet, exercise, massage, supplements and pain medications are all a part of managing hip dysplasia. Jumping and running should be avoided. Long walks and swimming are the best exercises for pets with hip dysplasia.

Most dogs recover well from surgery, can lead active lives free from pain, and have acceptable hip function (through range of motion varies with type of surgery). Follow-up appointments and x-rays will monitor healing and any changes in your pets hip dysplasia.

Providing carpeted ramps for stairs, the car, your bed or couch will help the pet get around comfortably. Hardwood or tile floors should be covered with rugs to prevent the pet from slipping.