Arthritis is inflammation of joints. There are several causes of arthritis: malformation of joints (such as hip dysplasia), abnormal development of the lining of joints (osteochondosis dissecans), immunological problems ('rheumatoid' arthritis), injuries and wear and tear.
Hip dysplasia is an inherited problem, but the genetics and development of abnormality can be very complex. Most breeds of dog in which it was particularly common now have Hip Scoring Schemes through which good breeders can make sure that they only breed from dogs which do not show the abnormality. Affected dogs have some degree of shallowness of the hip joint which allows abnormal movement of the joint with consequent abnormal wear which leads to arthritis.
Osteochondrosis dissecans (OCD) is a disease of the joint cartilage in the growing dog and affects large breeds from 6-15 months of age. It is insidious in onset and difficult to detect in its early stages. There is probably a genetic element in OCD but feeding high protein food and stresses on the joints, especially such as caused by landing heavily on hard surfaces will increase its severity. It will often settle with time and anti-inflammatory treatment, but some cases need surgery.
The group of immune mediated arthritis's are complex, but fortunately not very common.
Injuries caused by 'sporting' activities that dogs enjoy or obesity (and that is a common cause of joint injury) lead to damage inside the joint which leads to arthritis much as general wear and tear will.
Especially in dogs, and especially in overweight dogs, joints get worn and damaged by minor injuries which may not, of themselves, cause lameness. However the natural healing processes in the joint can go awry and lead to three main changes which become self-perpetuating: inflammation changes the nature of the synovial fluid which lubricates the joint, the cartilage lining of the joint which is rather like a nylon or plastic bearing on a bike or scooter becomes eroded and the inflammation in the lining of the joint leads to a build-up of bone around the joint.
Pictures courtsesy of Virbac UK Ltd, manufacturers of Fortaflex
Treatment of arthritis is a matter of managing a damaged joint and is unlikely to result in a cure. Removing the cause before arthritis develops is the only way to cure the joint. Because arthritis is painful, the affected animal is lame, or sometimes just seems stiff and doesn't use the limb as much as before so that muscles waste away. Owners often don't think their pet has pain from an arthritic joint as it doesn't cry out: if it DOES cry out it is in SEVERE pain. Most humans with arthritis rarely make a noise about it, but ask them if it hurts! The pain is mainly caused by the inflamed joint lining. Treatment with anti-inflammatory drugs will reduce this inflammation and so reduce the pain. The drugs are often also pain-killers. So treatment will improve the quality of the arthritic pet's life. Besides that, the inflammation is causing a worsening arthritis which will restrict the useful life of the joint. By controlling this inflammation with drugs, we can increase the lifespan of the joint. So treatment is doubly beneficial: better life and longer life!
There are many different treatment approaches to arthritis and it is often necessary to try more than one to find the best effects in any individual patient. I currently use non-steroidal anti-inflammatories (such as Metacam), corticosteroids, nutraceuticals (such as green lipped mussel extract, glucosamine products, especially Seraquin) and magnetotherapy. The aim is to allow good use of arthritic joints for as long as possible.There is a web site bringing together owners of disabled pets. Click this link.> Go to top of page