Hip dysplasia is a developmental disorder of the hip joint. Affected dogs do not have a normal ball (femoral head) and pelvic cup (acetabulum) joint that allows for normal hip function but instead the ball partially slips out of the cup during various movements of the leg. Over time, the abnormal hip joint develops arthritis because of the excessive wear on the affected cartilage structures. The degree of abnormal formation of the hip determines whether symptoms are present at a young age or how fast symptoms will develop as a dog ages.
Prevention of Hip Dysplasia
Development: The development of hip dysplasia is determined by both genetic and environmental factors. The incidence is very high in puppies born from parents with hip dysplasia. This is the reason that in all breeds that are susceptible to hip dysplasia the bitch and sire must be checked for hip dysplasia prior to breeding.
Diet: The incidence of hip dysplasia is also influenced by diet, body weight and exercise. Orthopedic specialists and nutritionists recommend feeding a reduced calorie and reduced protein puppy diet to slow down the growth rate of the large breed dogs. In addition, it is very important to keep these puppies lean. Exercise: The type and amount of exercise in young dogs can also influence the development of hip dysplasia. Regular “play” type of exercise is very important in the development of all the muscles of the body, which in turn helps to maintain joint strength.
Inappropriate exercise includes: jogging or extended walks beyond a 1/4 mile until the puppy is full grown. The reason long walks create a problem is that the same muscles are used over and over. As the muscles fatigue, the joints loosen and the hip joint can be damaged.
An affected dog with hip dysplasia can have symptoms ranging from a lameness and disability to no outward symptoms at all. Some of the signs may include the following:
- lameness that worsens after exercise
- a waddling type of gait
- difficulty rising
- Pain with movement of the hip
Diagnosis of Hip Dysplasia
The diagnosis of hip dysplasia is based upon clinical signs, the physical examination, radiographic studies and palpation of the hips under sedation. Orthopedic specialists recommend palpation and radiographs in all susceptible breeds between 4-6 months of age. The most accurate diagnostic test is palpation for joint laxity. A normal dog should not have any laxity in the hip joint such that the ball of the femur can be displaced from the pelvic cup. Radiographs are examined to determine the shape and depth of the cup of the pelvis and the shape and position of the femoral head.
The presence of hip dysplasia can result in minimal symptoms in some pets and severe debilitating symptoms in others. In young dogs that have abnormal palpation and abnormal x-rays there are typically two options:
1. Monitor the pet for signs of lameness while controlling body weight and utilizing proper exercise for muscle tone without further damaging the joint.
2. Pets with significant pelvic abnormalities or lameness will be referred to an orthopedic surgeon for a consultation.