Canine Arthritis is basically inflammation of a joint. When we talk about arthritis in dogs, we're usually referring to the leg joints, and describing dogs who are stiff and sore when they move. It is one of the most common reasons for a dog to visit their vet.
To understand what happens in dog arthritis, we need to know what a normal joint is like. The end of a bone, where it meets another bone, is covered by a thin layer of cartilage. This cartilage allows the bones to move smoothly against each other.
The whole joint is enclosed in a membrane, which also contains joint fluid. Joint fluid is a thick, clear liquid that acts as a shock absorber. It also helps to lubricate the joint as it moves.
When a dog's joint becomes arthritic, the cartilage becomes damaged, and the joint fluid becomes thin. There is less cushioning and lubrication, and wearing of the cartilage may result in bone rubbing on bone. The result is pain and a distressed dog.
Degenerative joint disease, also known as osteoarthritis, is the condition that most commonly occurs in older animals. It can affect any joint, but most dogs have pain in the legs and occasionally in the spine. Wear and tear over the years leads to erosion of the cartilage, especially if a dog is overweight. It can also occur in young animals if a joint has been injured, or if they were born with a joint abnormality, such as hip dysplasia.
Infectious arthritis can develop in dogs of any age. This develops when organisms enter a joint and multiply, causing pain and swelling of the joint. If only one joint is affected, the infection may have started from a wound to the joint which allowed infection to enter.
However, sometimes dogs can have infectious arthritis in many joints. In this type of arthritis, the bacteria usually come from another part of the body where there is an active infection. Some possible sources of bacteria are bad teeth, abscesses or urinary tract infections. The bacteria are carried in the bloodstream into all the joints of the body.
A dog's immune system is designed to protect the body from infections, but it can sometimes do more harm than good. It is involved in the development of a particularly painful type of arthritis. When it is stimulated, the immune system can form little particles of antibodies which are deposited on the lining of the joint membrane. These little particles then cause severe inflammation in the joint, with thickening of the membrane and movement of immune system cells into the joint. Symptoms of this type of arthritis include pain, but affected dogs can also show fever, lethargy and a poor appetite.
Just to make things more interesting, immune mediated arthritis can be further divided into erosive arthritis, and non-erosive arthritis. In erosive arthritis, also known as rheumatoid arthritis, the inflammatory cells that move into the joint release enzymes that wear away the cartilage and the underlying bone. The joint becomes very unstable and may become quite deformed.
Dogs with non erosive arthritis don't have any wearing of the cartilage, but they do have an increase in white blood cells in the joint fluid, and the joint fluid can turn into thick mucus clots.
Rheumatoid arthritis is a very poorly understood condition, and vets can't really explain why a dog develops this disease. Small breeds of dogs, including Poodles and Shetland Sheepdogs, appear to be affected more than other breeds. Perhaps there's some genetic tendency that hasn't yet been discovered.
Non erosive immune mediated arthritis usually occurs in conjunction with disease in another part of the body, for example cancer, inflammatory bowel disease or infection.
When it comes to degenerative joint disease, there is much more information available on possible causes of the condition. Some breeds of dog are much more likely to develop degenerative joint disease. For example, Labrador Retrievers and German Shepherd Dogs have an increased incidence of hip dysplasia, which is a hereditary abnormality of the hip joint. This leads to excessive stress and wear on the cartilage, and results in pain and stiffness.
Canine Obesity is a major cause of degenerative joint disease in dogs of any age. It's hard work for a joint to carry excessive weight, and if a dog is carrying excess weight, he will develop joint disease years earlier than a lean and healthy dog would.
Lastly, working dogs or athletic dogs such as those who compete in dog agility often put increased stress on their joints. This too can wear the cartilage, or damage ligaments, leading to osteoarthritis.
If a dog has infective arthritis, he will show the symptoms described above, but the affected joints are also usually swollen and painful. He will often have a fever, and be quite unwell. The lymph nodes in the area of the infected joints will be enlarged.
Similarly, dogs with immune mediated arthritis also have symtoms of fever, reduced appetite and lethargy. The lameness may come and go, and it may appear to affect one leg, then another. This is known as a shifting lameness.
Infective arthritis similarly is just an unfortunate occurrence. All dogs have the occasional accident, and that may include a wound to a joint, such as from a stick when you're out hiking. If your dog has an infection elsewhere in the body, early treatment with a suitable antibiotic can stop it spreading in the bloodstream and infecting the joints.
Dog fanciers can reduce the occurrence of degenerative joint disease in their favorite breed by only mating dogs who have normal joints. This will reduce the incidence of conditions such as hip dysplasia and elbow dysplasia, which often lead to osteoarthritis.
All dogs can develop osteoarthritis if they're overweight. Vets estimate that up to 40% of dogs are too heavy. This not only leads to joint pain, but may also lead to heart disease, skin fold infections and diabetes. You would be doing your dog a great favor if you restricted his diet and kept him lean. Discover the right way to feed your dog here.
If the arthritis is infectious, the appropriate treatment is antibiotics. It's often a good idea also to flush the joint to remove any thickened joint fluid and bacterial debris.
With the immune mediated diseases, treatment involves using medication such as corticosteroids and non steroidal anti inflammatory drugs to suppress the immune system, and to reduce the inflammation in the joint.
There are many approaches to treating degenerative joint disease. If the dog is overweight, he needs to go on a strict diet. Low impact exercise such as swimming or hydrotherapy is very important in maintaining joint function.
Pain relief is an important part of making sure your dog has a good quality of life. Non steroidal anti inflammatory drugs are the commonest prescription medications used to treat arthritis in dogs. They may cause side effects such as kidney disease and stomach ulceration, so it's important to perform blood tests on a regular basis, to make sure no problems are developing. As an alternative to these drugs, vets can prescribe a course of injections that will help support the cartilage in the joints and improve the thickness and cushioning effect of joint fluid.
Another popular and effective treatment is a glucosamine/chondroitin sulfate supplement such as Cosequin. These reduce inflammation and improve joint health, and can lead to significant improvement without the risk of side effects. Natural therapies such as acupuncture and massage can help ease a dog's pain. Physical therapy such as gentle bending and straightening of the affected leg may improve joint mobility.
The "last resort" treatment for arthritis is a procedure called arthrodesis. The cartilage on the end of the bones is surgically removed, and a bone graft is placed between the bones. The joint is then splinted, so the bone can heal together. The result is a joint that doesn't move any more. The leg will still be functional, but the joint is fused, so there is no more pain.
There may be things you can do to your dog's environment to make it easier for him to live with arthritis. Avoid polished floors, as they may be slippery, and your dog may fall. Give him a soft place to sleep, and keep his bed off the floor in a draft free environment. Try and avoid the need for him to climb stairs to get to his bed or food bowl.
Fortunately, there is help available for your dog. There are several options for treating arthritis that will ease his pain and improve his well being. It may take some trial and error to find what works best for him, but when you do, he'll again enjoy a comfortable pain free life.
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Please consult the services of a Professional Dog Trainer, Behaviorist or Veterinarian before implementing any of the advice contained on this site.