Dog Arthritis: Medications for Degenerative Arthritis
by Wendy C. Brooks, DVM, DipABVP
Degenerative joint disease is the number one cause of chronic pain in the dog and cat. The condition itself is the result of long term stresses and instability of a joint either as a result of old injury or of natural development of the joint in that individual. While surgery may be able to help in some situations, most of the time the degeneration of the joint cannot be reversed and treatment focuses on preventing progression of damage. Numerous products are available on the market; some are best combined with others and some cannot be combined. The following is a summary of options:
Aspirin is a non-steroidal anti-inflammatory drug or NSAID. It is effective in relieving pain due to inflammation as is occurring within the arthritic joint. It has the advantage of being readily available and inexpensive. It also has a relatively fast onset of action (other medications require at least one month of use to build up adequate levels in the joint). In some animals, however, it is simply not strong enough or it causes unpleasant side effects such as upset stomach or even intestinal bleeding. Aspirin also deactivates platelets (the blood cell responsible for clotting) and thus can promote bleeding should surgery or trauma occur.
* Cats metabolize aspirin extremely slowly and require a very low dose and a typical dosing schedule of twice a week usage. Dogs can use aspirin up to three times daily. * Because this medication is available in almost every pet-owning household, there may be a temptation to guess a dose based on the human dose. Do not be tempted to do this. Do not use aspirin or any other medication in your pet without veterinary guidance. * Enteric coating of aspirin has become popular in human products. This coating is a problem in animals and creates unpredictable absorption. This becomes dangerous when enteric coated aspirin tablets do not digest in the stomach and instead collect in the stomach until a toxic dose is reached. To avoid this disaster, use either aspirin made specifically for pets or aspirin with a powdery covering rather than the “hard candy” type enteric coating.
RIMADYL AND ETOGESIC
These medications are also NSAIDs. They were developed as an improvement upon aspirin and other NSAIDs developed for humans for which side effects have been problematic in animals. Rimadyl and Etogesic are both designed for indefinite use in dogs with minimal side effect potential. Rimadyl is given twice daily and Etogesic is given once daily.
Typically a short trial of one of these is prescribed to see if the effect is worth continuing; as with people, some individuals respond better to different NSAIDs. If the effect is good, then the medication can be continued. Some blood testing is recommended prior to long term use and every 6 months thereafter.
* Approximately one dog in 5000 will have a serious liver reaction to Rimadyl. Animals with histories of elevated liver enzymes, pre-existing liver disease, Cushing’s disease, or phenobarbital use should probably not take this medication. * Neither of these medications should be used in cats.
GLUCOSAMINE AND CHONDROITIN SULFATE
These products are cartilage components harvested chiefly from sea mollusks (i.e., cartilage is made up of glucosamine and chondroitin sulfate). By taking these components orally, the patient is able to have plenty of the necessary building blocks needed to repair damaged cartilage. It is also felt that these products may have some anti-inflammatory properties separate from their structural uses. Unlike NSAIDs, these products do not produce rapid results; one to two months are needed for them to build up to adequate amounts. There are numerous products available combining glucosamine, chondroitin sulfate, assorted vitamins, creatine (a muscle building block), omega 3 fatty acids, and more.
* Because these substances are classified by the FDA as nutriceuticals (i.e., nutrients with medicinal properties) rather than as drugs. The usual rigorous testing for efficacy has not been required. As a result, the optimal dosage has not been determined and almost every product has a different dose recommendation. Some experimentation may be necessary. * These products are not likely to be helpful for spinal arthritis as the joint composition of an intervertebral disc (the joint of the spine) is totally different from those of other bones. * These products can be used in both dogs and cats. * These products often complement treatment with NSAIDs.