Elbow dysplasia is the disease most commonly implicated in front limb lameness (limping) in dogs. It occurs when the bones that make up the elbow joint don't come together just right, leading eventually to painful movement in the forelimb.
The elbow is made up of the humerus (the long bone of the upper forelimb), which communicates at the joint with the radius and ulna (the two bones that comprise the lower forelimb below it). All these bones need to fit together just right for the elbow to withstand a lifetime of wear and tear. When they don't, "elbow dysplasia" is the descriptive term applied to the condition and its resulting symptoms.
To make matters even more confusing, a variety of diseases specific to the elbow are considered different forms of elbow dysplasia:
Ununited anconeal process (UAP)
Fragmented medial coronoid process (FMCP)
Osteochondritis dessicans of the medial humeral condyle (OCD)
Ununited medial epicondyle (UME)
All these problems may ultimately affect the elbow because the joint just wasn't "made right." These variations of elbow dysplasia have in common one additional thing: They invariably lead to elbow arthritis.
Because arthritis (also known as "ostoearthritis" and synonymous with joint inflammation) is the result of the uncomfortable movement when the bones of the joint aren't properly aligned, this problem is sometimes confused by owners as a normal process of aging dogs. Nonetheless, the joint malformation that causes elbow dysplasia is the most common underlying cause of elbow arthritis in dogs of all ages. So think of the arthritis as a symptom we need to treat--not as the cause itself.
Though trauma to the elbow can lead to the same kinds of changes to the elbow produced by elbow dysplasia, this disease is most commonly the result of genetic factors that lead to less than optimal joint conformation.
Symptoms and Identification
Dogs affected with elbow dysplasia may show signs of mild to moderate pain and lameness in the forelimbs as early as four months of age. But some will not show signs of this disease until later in life. Both elbows are typically involved, but one may be much more grievously affected.
The timing of the symptoms' arrival is typically related to the severity of the joint's abnormality. Dogs who show no signs until later in life are typically those who have already developed arthritis (inflammation in the joint) from uncomfortable rubbing of the joint's misaligned components.
Diagnosis of elbow dysplasia is typically arrived at through X-rays confirming visible changes to the joint. But a history of front-limb lameness in a young dog or palpable thickening of the elbow (evidence of arthritis) usually raises the alarm. CT scans of the area can also be very helpful to identify the exact version of elbow dysplasia present, but a surgical exploratory (usually through arthroscopy, but also through open-joint surgery) is considered the best way to determine the extent of the joint's damage.
Large breed dogs are most affected. Here are the top twenty breeds affected, courtesy of the Orthopedic Foundation for Animals (OFA):
The treatment of these cases varies according to the exact form the disease has taken and the stage at which it presents. If possible, removing loose flaps of cartilage and "smoothing out" the cartilage in the joint is undertaken. However, this is best achieved in the disease's earliest stages. After arthritis has set in, it becomes increasingly difficult and unreliably beneficial to enter into a surgical treatment of the affected joint.
Arthroscopy (surgically introducing a fiberobtic scope) is commonly considered the best method for handling cases that are amenable to surgical treatment, but open-joint surgery is not inadvisable in the hands of a capable surgeon. Board-certified veterinary surgeons are almost uniformly employed in the surgical diagnosis and treatment of elbow dysplasia, in all its forms.
Elbow replacement surgery is currently being developed but, unfortunately, it's still largely unavailable. It may take years for a workable surgical solution to make its way to a veterinary specialty hospital near you.
Options for treatment also include pain relieving drugs, such as pet-specific anti-inflammatory drugs (e.g., carprofen, meloxicam, etc.) and opiates (such as tramadol). Long-term use of nutraceuticals (like glucosamine and fatty acids) have also been found to be of some limited assistance.
Yes, it's pricey to treat elbow dysplasia. Whether your dog is experiencing early-stage pain or end-stage arthritis, the costs can add up. For young dogs who are candidates for surgical options, the cost of surgical diagnosis and treatment can range from $1,500 to $4,000 per elbow.
Preventing elbow dysplasia is largely a breeder's job. Those who plan the genetic future of their dogs' offspring by appropriately breeding dogs free of this trait, in any of its forms, are effectively at the forefront of prevention.
The Orthopedic Foundation of America (OFA) will grade elbows on a scale of I-III to assist breeders in the prevention of elbow dysplasia by removing affected pets from the breeding pool.(2) This test, however, which is based on X-rays, is not considered very sensitive.
That's why several veterinary programs are currently focusing their energies on this issue.. In particular, the use of QTC (quantitative CT scans) of the joint is a new method pioneered by the veterinary school at the University of California at Davis.(3) The results of their current studies may well allow for early detection of less severe forms of elbow dysplasia so that breeders can make better decisions about which dogs should be removed from the genetic pool.
Orthopedic Foundation for Animals (OFA)