What is it?
Hip dysplasia is a common orthopedic problem seen in dogs. It affects virtually all breeds of dogs but is more problematic in large and giant breeds. Hip dysplasia in the younger animal is usually characterized by marked pain or lameness while a more chronic form has a gradual onset of symptoms such as mild, intermittent pain, stiffness and restricted range in motion as the dog ages.
The hip joint is a ball and socket joint: the head of the femur (thigh bone) is the ball, and the pelvic bone forms the socket. Hip dysplasia occurs when the ball is loose in the socket.

Signs and Symptoms
Early signs of hip dysplasia include an unwillingness to stay out in the cold, difficulty in rising on the hindlegs or climbing stairs, and lack of stamina in work or play. As the disease gets worse, some dogs will shift their weight forward off the rear quarters. Dogs with later stages may bunny hop - hop on both hind limbs when walking, or may have intermittent lameness that becomes chronic after age four. You may feel the joint's looseness, and in chronic cases you may hear cracking noises. Then again, you may have a dog who exhibits no symptoms at all or very minimally at the least.

Causes
Genetics is the foremost causative factor of canine hip dysplasia. Without the genes necessary to transmit this degenerative disease, there is no disease. Hip dysplasia is not something a dog gets; it either is dysplastic or it is not. Hip dysplasia is genetically inherited. While environmental effects, to include nutrition and exercise, may play a part in mitigating or delaying the onset of clinical signs and clinical symptoms, hip dysplasia remains a genetically transmitted disease.
Other diseases, infections or trauma can produce clinical signs suggestive of hip dysplasia. In the older dog, trauma from younger years may manifest itself as arthritic deterioration. A little bit more unusual is to have viral penetration of the joint capsule with resultant damage to articular cartilage, or the epiphyseal surfaces of the femur.
There is some evidence that preventing rapid growth reduces the extent to which the adult dog will manifest hip dysplasia. Decreasing the dog's food consumption during its growth period seems to correlate well with normal hips.
Many researchers conclude that early fusion may lead to bone and cartilage deviations which then could predispose the animal to future dysplasia. Given that joint laxity is at least one of the factors governing the onset of hip dysplasia, then any process that retards this condition could possibly minimize the severity of the disease. It also is conceivable that retardation of joint laxity could delay the onset of the physical appearance of the disease. Remember, loose joints and hip dysplasia are found together.

Diagnostics
To reach a definitive diagnosis your veterinarian will have to take radiographs (x-rays).
Currently the methods used are: OFA (Orthopedic Foundation for Animals) and PennHIP.

OFA
Radiographs submitted to the OFA must follow certain guidelines. To obtain this view, the animal must be placed on its back in dorsal recumbency with the rear limbs extended and parallel to each other. The knees are rotated internally and the pelvis is symmetric. Anesthesia is recommended. Radiographics of animals 24 months and older are independently evaluated by three randomly selected, board-certified veterinary radiologists from a pool of 20 to 25 consulting radiologists throughout the USA in private practice and academia. Each radiologist evaluates the animal's hip status considering the breed, sex, and age. Radiographs may be done at 6 months for a preliminary evaluation.
Evaluations done by the Orthopedic Foundation for Animals falls into seven different categories: Excellent, Good, Fair, Borderline, Mild, Moderate, Severe.
Hip grades of excellent, good and fair are within normal limits and are given OFA numbers. This information is accepted by AKC on dogs with permanent identification (tattoo, microchip) and is in the public domain. Unless the owner has chosen the open database, dysplastic hip grades are closed to public information.

Excellent hips show superior conformation with a very tight joint space and almost complete coverage of the hip ball by the hip socket.

Good hips are slightly less than superior, most of the hip socket covers the hip ball and there is a congruent joint space.

Fair hips are assigned where minor irregularities in the hip joint exist. The hip joint is wider than a good hip phenotype. This is due to the hip ball slightly slipping out of the hip socket causing a minor degree of joint incongruency (called sublaxation). There may also be slight inward deviation of the weight-bearing surface of the hip socket causing it to appear slightly shallow.

Borderline: there is no clear cut consensus between the radiologists to place the hip into a given category of normal or dysplastic.

To increase the accuracy of a correct diagnosis, it is recommended to repeat the radiographs at a later date (usually 6 months). Most dogs with this grade (over 50%) show no interval change in hip conformation over time and receive a normal hip rating: usually a fair hip phenotype.
Mild: there is significant sublaxation present where the hip ball is partially out of the hip socket causing an incongruent increased joint space. The hip socket is usually shallow only partially covering the hip ball.
Moderate: there is significant sublaxation present where the hip ball is barely seated into a shallow hip socket causing joint incogruency. There are secondary arthritic bone changes usually along the femoral neck and head (termed remodeling), acetabular rim changes (termed osteophytes or bone spurs) and various degrees of bone changes called sclerosis.
Severe: this is assigned where radiographic evidence of marked dysplasia exists. There is significant sublaxation present where the hip ball is partly or completely out of a shallow hip pocket. Secondary arthritic bone changes may exist. 

Since hip dysplasia is a chronic, progressive disease, the older the dog, the more accurate the diagnosis of hip dysplasia (or lack of). At 2 years of age, the reliability for a radiographic diagnosis of hip dysplasia is 95% and as the dog ages, the reliability steadily increases. Radiographs should definitely be resubmitted if they were taken during times of known environmental effects such as physical inactivity and high estrogen levels during or around the time of a heat cycle which could lead to a false diagnosis of mild hip dysplasia.

PennHIP
PennHIP is a scientific method to evaluate a dog for the susceptibility to express the radiographic signs of hip dysplasia. The radiographic procedure involves a special positioning of the dog so that the dog's passive hip laxity can be accurately measured. In simple terms, passive hip laxity refers to the degree of looseness of the hip ball in the hip socket when the dog's muscles are completely relaxed. Research has shown that the degree of passive hip laxity is an important factor in determining susceptibility to develop Degenerative Joint Disease (DJD) later in life. Radiographic evidence of hip DJD, also known as osteoarthritis, is the universally accepted confirmation of Canine Hip Dysplasia. PennHIP differs in some very fundamental and important ways. As with all diagnostic tests, PennHIP's accuracy is not 100%. Passive hip laxity is objectively measured and the resulting hip evaluation report is not issued in a pass/fail framework.
PennHIP's evaluation protocol specifically measures passive joint laxity. Based on the degree of laxity, the individual dog is than ranked relative to other members of the same breed. For example, a dog receiving a ranking in the 70th percentile it means that 30% of its breed members have hips that are tighter.
As shown in studies, dogs with tighter hips are less likely to develop CHD and pass that genetic tendency on future generations. Positioning the dog differs from conventional hip-extended position to screen for hips. Three separate radiographs are made during an evaluation. The first is a compression view where the femurs are positioned in a neutral orientation and the femoral heads are pushed fully into the sockets. The second radiograph is the distraction view, the hips are again positioned in a neutral orientation and a special positioning device is used to apply a force to cause the hips to displace laterally. This position is the most accurate and sensitive for showing the degree of passive laxity. Passive laxity has been show to correlate with the susceptibility to develop DJD. A third radiograph is also included for the sole purpose of examining for any existing joint disease such as osteoarthritis.
PennHIP evaluations may be performed as young as 16 weeks of age.

Treatment
Conservative treatment is favorable in most circumstances. Response to conservative therapy depends on the dog's threshold of pain and the owner's ability to monitor the dog. One of the most effective treatments is the control of the dog's weight. Even small amounts of weight loss are productive. Restricted activity also should be considered not only to avoid excessive wear on the affected joint, but to control transient inflammation.
Owner-conducted physical therapy is an indispensable component of treatment. Heat, followed by range of motion exercise, may provide temporary relief. Simple measures such as bedding changes can make a difference.

Other measures

Chiropractic
Although not a treatment for hip dysplasia, chiropractic is available to that segment of the dog population not suffering with the genetic disease, but from sublaxation of the spine between the eighth and tenth vertebra

Acupuncture
A great body of anecdotal evidence exists to suggest that acupuncture has potential for at least temporarily reducing pain and promoting natural healing.

Drug Therapy
Most of the pharmacological treatment alternatives function by reducing the inflammatory response. These drugs include corticosteroids and a variety of NSAIDS (non-steroidal anti-inflammatory drugs). Although useful in the acute stage, corticosteroids are inappropriate for long-term use due to their undesirable side effects.
NSAIDS have some drawbacks as well. Aspirin may cause vomiting and bloody stools and bleeding times can be prolonged.
Other drugs used include phenylbutzone (bute) which can depress bone marrow formation.

Nutritional Therapy
Anti-oxidant vitamins, d-alpha-tocopherals (the most biologically available form of Vitamin E) and calcium ascorbate are not useful for acute symptoms but if taken daily and consistently, they can reduce inflammation without any detrimental side effects. They are unable, however, to repair cartilage that has been compromised.

Glyco-Flex is a freeze-dried preparation and is a complex mixture of proteins, amino acids, chelated minerals, enzymes, and vitamins.

Cosequin is a patented nutraceutical containing glucosamine HCL, purified chondroitin sulfate and manganese ascorbate.

GAGS
Glycosaminoglycans. An injectable form called Adequan is a chondro-protective drug. It promotes the synthesis of cartilage matrix components and slows down the destruction of these cartilage components. This drug should not be used in dogs with blood coagulation problems or with any other drug that interferes with normal blood clotting mechanisms.

Surgical Intervention
Any surgical correction of hip dysplasia is a serious procedure, young or mature. Some dogs may never develop any significant lameness and therefore are not subject to a surgery they may never need.
Surgeries for the younger patient include triple pelvic osteotomies (TPO) and intertrochanteric varus osteotomies. TPOs are suggested for immature patients who have not developed irreversible cartilage or bone changes in the hip joint. This surgery could achieve pain-free activity, stabilization of the hip with natural tissues, and reduction of progression of radiographic signs of degenerative joint disease.
Total hip replacements are good for large mature dogs that are unresponsive to conservative therapy and are otherwise healthy animals. This procedure replaces the diseased joint with a high-density plastic socket and a stainless steel ball that is cemented into place. Complications, including dislocation of the joint post-operatively or loosening of the cement that holds the joint together, occur in 5-10 percent of total hip replacements. If the prosthesis gets infected, removal of the artificial joint and cement is required to cure the infection.

Prevention
Excessive growth and weight is an important factor. In addition, supplemental feeding of calcium should not be encouraged. Strongly associated with a high calcium intake is disturbed enchrondal ossification (growth plate anomalies) and osteochondrosis which is a disturbance of bone formation within the cartilage. Chronic, high calcium intake in large breed dogs has also been associated with hypercalcemia, elevation of a liver enzyme alkaline phospatase, retardation of and delayed maturation of cartilage

ELBOW DYSPLASIA

For elbow evaluations, there are no grades for radiographically normal elbow. The only grades involved are for abnormal elbows with radiographic changes associated with developmental degenerative joint disease (elbow dysplasia).
Abnormal elbows are reported as:
Grade 1 - minimal bone change along anconeal process of ulna (less than 3 mm)
Grade 2 - additional bone proliferation along anconeal process (3-5 mm)
Grade 3 - well developed degenerative joint disease with bone proliferation along anconeal process being greater than 5mm. Like the hip certification, OFA will not certify a normal elbow until the dog is 2 years of age.

This information is provided for educational purposes only and is not a substitute for medical advice. It is not to be used for diagnosing or treating a health problem, nor is it a substitute for professional care. If you suspect that your dog may have a health problem, please consult your veterinarian.