Affects: Dogs
In dogs, hip dysplasia is an abnormal formation of the hip socket that, in its more severe form, can eventually cause lameness and arthritis of the joints. It is a genetic (polygenic) trait that is affected by environmental factors. It is common in many dog breeds, particularly the larger breeds, and is the most common single cause of arthritis of the hips.
Symptoms: Dogs with hip dysplasia may exhibit the following signs and symptoms:
Decreased activity
Decreased range of motion
Difficulty or reluctance rising, jumping, running, or climbing stairs
Lameness in the hind end
Causes And Effects: Hip dysplasia may be caused by a femur that does not fit correctly into the pelvic socket, or poorly developed muscles in the pelvic area. Large and giant breeds are most susceptible to hip dysplasia (possibly due to the body mass index (BMI) of the individual animal), though many other breeds can suffer from it. The Orthopedic Foundation for Animals maintains a list of top 100 breeds affected.
To reduce pain, the animal will typically reduce its movement of that hip. This may be visible as "bunny hopping", where both legs move together, or less dynamic movement (running, jumping), or stiffness. Since the hip cannot move fully, the body compensates by adapting its use of the spine, often causing spinal, stifle (a dog's knee joint), or soft tissue problems to arise.
The causes of hip dysplasia are considered heritable, but new research conclusively suggests that environment also plays a role. To what degree the causality is genetic and what portion environmental is a topic of current debate. Neutering a dog, especially before the dog has reached an age of full developmental maturity, has been shown to almost double the chance he or she will develop hip dysplasia versus intact dogs or dogs that were neutered after reaching adulthood. Other environmental influences include overweight condition, injury at a young age, overexertion on the hip joint at a young age, ligament tear at a young age, or repetitive motion on forming joint (e.g. jogging with puppy under the age of 1 year). As current studies progress, greater information may help provide procedures to effectively reduce the occurrence of this condition.
It is most common in medium-large pure bred dogs, such as Newfoundlands, German Shepherd Dogs, retrievers (such as Labradors, Tollers, or Goldens), Rottweilers and Mastiffs, but also occurs in some smaller breeds such as spaniels and pugs.
Diagnosis: Hip dysplasia is diagnosed with radiographs of the pelvis.
It is also common to X-ray the spine and legs, as well as the hips, since soft tissues can be affected by the extra strain of a dysplastic hip, or there may be other undetected factors such as neurological issues (e.g. nerve damage) involved.
Treatment: There is no complete cure, although there are many options to alleviate the clinical signs. The aim of treatment is to enhance quality of life.
Most dogs with hip dysplasia do not need surgery as they do very well with a home physical therapy program, keeping trim and strong, and using pain medication as needed.
If the problem cannot be controlled with medications, then often surgery is considered. There are traditionally two types of surgery - those which reshape the joint to reduce pain or help movement, and hip replacement which completely replaces the damaged hip with an artificial joint, similar to human hip replacements.