Arthritis is a complex condition involving inflammation of one or more joints. There are many causes of arthritis in pets. In most cases, the degree of arthritis is related to the age of the animal.
What causes arthritis?
Arthritis can be classified as primary arthritis such as rheumatoid arthritis and secondary arthritis which occurs as a result of joint instability that leads to damage of the subchondral bone that line the joints. Secondary arthritis is the most common form diagnosed in veterinary patients. The most common type of arthritis is osteoarthritis (OA) which is also known as degenerative joint disease (DJD). Some common causes of secondary arthritis include hip dysplasia, obesity, cranial cruciate ligament rupture, and so forth.
Other causes include joint infection, often as the result of bites or following joint trauma and damage.
Rheumatoid arthritis is an immune mediated, erosive, inflammatory condition. Cartilage and bone are eroded within affected joints and the condition can progress to complete joint fixation (ankylosis). It may affect single joints or multiple joints may be involved (polyarthritis). In certain dog breeds Rheumatoid Arthritis (RA) factors can be detected with blood tests. Other types of immune mediated arthritis can be non-erosive, such as arthritis that is associated with Systemic Lupus Erythematosis (SLE). SLE is often accompanied by other clinical signs in addition to the arthritis.
Infective or septic arthritis can be caused by a variety of microorganisms, such as bacteria, viruses and fungi. Septic arthritis normally only affects a single joint and the condition results in swelling, fever, heat and pain in the joint. With septic arthritis, your pet is likely to stop eating and become depressed.
How do we treat arthritis?
Treatment will depend on the cause of arthritis. Immune mediated and rheumatoid arthritis are usually treated with high doses of corticosteroids, often with dramatic improvement. The control of these conditions often involves the long-term use of corticosteroids and other drugs such as immunosuppressive or cytotoxic agents.
The treatment of septic arthritis involves determining the type of microorganism involved and its antibiotic sensitivity. Antibiotics are usually administered for a minimum of a month and analgesics (pain relief medications) are necessary to combat pain and inflammation.
Analgesics such as non-steroidal anti-inflammatory drugs (NSAIDs) are the most common form of treatment for osteoarthritis. It is important to select these medications with care since some dogs are more sensitive than others to the potential side-effects of analgesics. The most common side-effects of analgesics include decreased appetite, vomiting and diarrhea. Pre-medication blood tests must be performed to make sure that the pet can safely metabolize and eliminate the medication and then periodic blood tests are necessary to ensure continued safe usage.
If you have any concerns or questions about the administration of any medication, please discuss theme with your veterinarian.