Some of the drugs used to treat arthritis
Osteoarthritis
Osteoarthritis is a progressive deterioration of the cartilage that lines the joint. It is probably more appropriately known as degenerative joint disease (D.J.D.)
D.J.D. is probably the most common skeletal disease encountered in dogs though the actual incidence is unknown. Any breed of dog or cat is susceptible to osteoarthritis. It can develop at any age but is most commonly seen in older pets of either sex. D.J.D. is not thought to be hereditary (i.e. passed from one generation to the next) unless there is a known hereditary cause e.g. hip dysplasia.
What causes osteoarthritis?
There are essentially two broad causes of osteoarthritis:
1. Primary. This is thought to be due to long term exercise combined with ageing.
2. Secondary. This form is the most common type of arthritis seen and results from an initiating cause such as hip dysplasia, joint fractures, ligament damage or an infected joint.
How does osteoarthritis develop?
Once the cartilage covering the joint surface (known as articular cartilage) is damaged it releases chemicals called inflammatory mediators. These chemicals act on the cartilage to destroy a substance called proteoglycan. Proteoglycan is responsible for keeping the cartilage smooth and more importantly elastic so that it can rebound when forces, such as occurs with walking, are exerted on it. Without proteoglycan the cartilage cracks and begins to disintegrate. This causes inflammation and pain in the joint.
What are the signs of osteoarthritis?
Dogs and cats suffering from D.J.D. often show:
- intermittent lameness that slowly becomes more severe and frequent with time
- lameness that becomes worse with exercise, long periods of lying down and/or periods of cold weather
- some dogs will have a stiff gait rather than lameness
- reduced range of joint motion
- joint swelling or thickening
- pain
- muscle wastage due to disuse
How is osteoarthritis diagnosed
Osteartthritis is diagnosed on the basis of clinical signs, physical examination, history, predisposing factors and radiology.
Radiology is useful to confirm osteoarthritis and to monitor changes over time which can help with prognosis.
How is osteoarthritis treated?
The aims of treating osteoarthritis are:
1. Reduce pain
2. Prevent or slow further degeneration
3. Restore function to as near normal as possible.
These aims are achieved by:
1. Exercise. The amount of exercise should be limited to a level that minimizes aggravation of the signs of arthritis. Non-weight bearing exercises such as swimming are excellent for dogs suffering from arthritis.
2. Diet. Overweight pets should be put on a diet to reduce the stress placed on the affected joint(s).
3. Medication. There are essentially two types of medications used:
(i) Anti-inflammatories.
Drugs such as Rimadyl, Metacam, Etogesic, Beautamav and Ketofen are used to reduce the pain and inflammation.
(ii) Anti-arthritics. Drugs such as Cartrophen Vet are used to slow the progression of arthritis.
(iii) Dietary supplements which help the cartilage maximize its repair and minimize the inflammation will also help.
4. Surgery. Surgery may be considered to correct any underlying cause of the arthritis e.g. ruptured cruciate ligament.
The earlier treatment is instituted the better the expected results.
Some of the drugs used to treat arthritis