Hip dysplasia is the most common skeletal development defect in dogs.  Cats can develop hip dysplasia too (Feline Hip Dysplasia). Hip dysplasia is a condition in which abnormal formation results in an unstable hip joint.  It is a subluxation (laxity, instability) of the femoral head (ball) in relationship to the acetabulum (socket).  The hip or coxofemoral joint is often referred to as a ball-and-socket type of articulation.  In canine hip dysplasia the socket portion (acetabulum) is too shallow to accept the ball portion (femoral head).  More information about this disease is illustrated below and by clicking on the Hip Dysplasia website link to the Veterinary Information Network Pet Health Library:   Hip Dysplasia

Not all dogs with hip dysplasia are affected to the same degree.  The disease can be very mild and cause no signs at all, or it may cause severe lameness.  While the disease usually affects both hips, occasionally it only affects one side.  The syndrome of hip dysplasia develops primarily within the first 6 to 8 months of life but may go un-noticed until much later in age. As the affected dog ages, the hips gradually become arthritic and may degenerate to cause total crippling of the rear limbs. 

An evaluation of the animal's hip status considers approximately 9 different anatomic areas of the hip.

1. Craniolateral acetabular rim
2. Cranial acetabular margin
3. Femoral head (hip ball)
4. Fovea capitus (normal flattened area on hip ball)
5. Acetabular notch
6. Caudal acetabular rim
7. Dorsal acetabular margin
8. Junction of femoral head and neck
9. Trochanteric fossa

The veterinarian is concerned with deviations in these structures from the breed normal. The veterinary radiologist will grade the hips with one of seven different physical (phenotypic) hip conformations: normal which includes excellent, good, or fair classifications, borderline or dysplastic which includes mild, moderate, or severe classifications.

Seven classifications are used to establish heritability information for a given breed:

1. Excellent
2. Good
3. Fair
4. Borderline
5. Mild
6. Moderate
7. Severe

                  NORMAL HIP                                  MODERATE DYSPLASIA                 SEVERE DYSPLASIA & Arthritis

The exact cause of hip dysplasia is unknown, but it is believed to develop because the skeleton grows faster than the supporting muscles.  The imbalanced growth rate is influenced by heredity and diet.  Other unknown factors may influence the development and severity of hip dysplasia.  It is extremely important to keep your pet within the normal weight range and avoid obesity.  Overweight pets develop arthritis or ligament problems sooner.

DOGS Diagnosed with Hip Dysplasia should not be bred.

Following are some of the potential clinical signs of canine hip dysplasia:

♦              Hind limb lameness that may be more apparent after prolonged exercise.

♦              Waddling, swaying or bunny-hopping type of gait

♦              Stiffness that eventually resolves as the dog “warms-up”.

♦              Difficulty in rising

♦              Reluctance to move, climb stairs, or stand on rear legs.

♦              Change in temperament

♦              Pain caused by movement of the hip joints when running or jumping

♦              Poorly developed muscles in rear legs

♦              Leg-carrying lameness.

Radiographic (Xray) studies while under light sedation are necessary to confirm diagnosis of dysplasia.

Treatment options vary from simply restricting exercise to oral medication supplements +/- injections,

to surgery, depending on severity of the condition. 

Proper treatment often allows affected pets to live reasonably normal lives. 

The doctor will discuss the prognosis (medical forecast) for your pet.

Notify the Doctor if Any of the Following Occur

♦              Your pet shows increasing discomfort or lameness in the rear legs.

♦              Your pet develops weakness or lameness in the front legs.

♦              Your pet has vomiting, increased urination, or increased water intake.