Degenerative Joint Disease in Dogs
What is DJD?
Joints are the connection between two or more bones. The end of the bone is covered with a smooth layer of cartilage, called "articular cartilage" and the joint is 'held together' by a tough fibrous joint capsule that surrounds it. A thin membrane that produces joint fluid lines the joint capsule. This fluid acts as a lubricant and carries nourishment to the articular cartilage. The articular cartilage does not have any blood supply of its own to supply it with nourishment and oxygen. Instead, it receives its nourishment from small vessels in the underlying bone and through absorption from the joint fluid.
As our pets age, the tissues lining the joints may deteriorate and degenerate. Degenerative Joint Disease (DJD) refers to arthritis or osteoarthritis which is the result of the gradual deterioration of the articular cartilage within one or more the joints (see also the Client Education Handout "Arthritis: General Information").
"Obese patients are more likely to develop DJD, as a direct result of the stress that the excessive weight puts on the joints."
This smooth resilient cartilage degenerates, becoming brittle. With severe DJD, the degenerated cartilage may actually split away from the bone and become loose within the joint. DJD can follow a number of joint diseases including infection and may follow surgery. Obese patients are more likely to develop DJD, as a direct result of the stress that the excessive weight puts on the joints.
Although DJD is not usually an inflammatory disease, mild inflammation plays a part in causing clinical signs. When the cartilage cells become damaged, they release substances that result in inflammation, causing pain and further damage to the cartilage. Thus, once DJD begins it can become a vicious cycle.
Is there anything I can do to prevent DJD?
Many dogs suffering from DJD are overweight. If your dog is overweight, it is imperative that he or she loses weight in a controlled manner. So called "light diets" are helpful in preventing excessive weight gain, but rarely are useful for losing weight. There are many weight reducing diets available that work very well. We can help you design an appropriate weight loss program for your pet.
Can the condition be cured?
Most of the damage caused by DJD is irreversible. Fortunately, modern analgesics can effectively control pain with few side effects. In addition, medications are available that can slow the progress of the disease and promote cartilage healing.
What about pain relief?
Many of the early analgesics caused gastrointestinal upset and were hard on the kidneys and liver.
"...modern arthritis medications that have fewer side effects and are available in formulations that are easy to administer. "
Research advances have lead to the development of modern arthritis medications that have fewer side effects and are available in formulations that are easy to administer. You should not give your pet any pain reliever meant for human use without specifically being told to do so by your veterinarian, since this could cause serious problems. If you think your pet's medication is causing side effects, please discontinue its use and contact your veterinarian.
How can the progression of DJD be slowed?
Ongoing arthritis research has lead to the development of drugs that are effective in controlling the destruction of cartilage in dogs with DJD. They work by:
- improving the blood supply within the joint
- preventing formation of some of the harmful enzymes that continue the destruction of cartilage within the joint once it has started
- promoting the formation of fibrous tissue to heal damaged areas
- promoting cartilage repair
What about diet supplements?
There are certain products that are described as nutritional supplements rather than pharmaceuticals, (i.e. drugs). These products have been termed nutraceuticals. Nutraceuticals include glucosamine (a glycosaminoglycan) and chondroitin sulfate. There are some small research studies and numerous anecdotal case histories that suggest these products are beneficial, and they are free of side effects. Numerous products that contain glucosamine and/or chondroitin, along with other trace elements and vitamins, and that are palatable to dogs, are commercially available.
Omega-3 fatty acids have long been proven to help humans suffering from osteoarthritis and DJD. Their usage in veterinary medicine is growing in popularity and they are a useful treatment in conjunction with other medications for any patient experiencing DJD or osteoarthritis.
If you have any questions or concerns regarding treatment, please do not hesitate to contact your veterinarian.