Arthritis: A Multimodal Treatment Approach (Updated 23 December 2013)
Degenerative joint disease is the number one cause of chronic pain in dogs and cats and the number one cause of humane euthanasia. The condition is exacerbated with injury or joint stressors such as obesity. Some breeds are genetically predisposed to the formation of arthritis in abnormally formed joints. Surgery may be recommended in some instances. Arthritis cannot be reversed. Efforts are aimed at the management of the discomfort and in trying to slow down the progression of the disease. Combinations of different medications work together to accomplish this best. Although we discuss medications here, it is important to note the role that rapid growth rate and obesity play in the development of skeletal disorders. (Large breed puppy formulations have been created with this in mind.)
Proper exercise and appropriate body weight have been shown to influence the quality of a pets life. Lean fed dogs have been statistically shown to live as much as 3 years longer. Swimming is excellent physical therapy for the arthritic pet, helping to build muscle mass while putting very little stress on the joints. Physiotherapy including massage and gentle flexion/extension of the joint may also help. Remember, treatment for joint disease is likely to involve a combination of medications in addition to physical activity.
These products do not have the scientific studies for efficacy and safety done. Some experimentation with products and dosing may be required. The effects may not be seen for weeks. They have been used safely in both dogs and cats and will complement the anti-inflammatory properties.
Glucosamine and Chondroitin Sulfate
These are thought to have anti-inflammatory effects and provide the necessary components for cartilage repair. They require several months to evaluate response. There are a number of combined products on the market, as well as newer joint diets that have these included. Ensure that fatty acids are not given to a pet with a history of pancreatitis or miniature schnauzers that are prone to it.
Omega Three Fatty Acids
Certain dietary fats, typically cold water fish oils, have been found to have anti-inflammatory properties. While this finding has primarily been used in the treatment of itchy skin, many arthritic dogs and cats have also benefited from supplementation. These products require at least one month to evaluate a patient’s response. Although helpful, the changes will not usually be dramatic. Flax seed is not readily converted to fatty acids in cats and dogs, although used in humans. The appropriate dose is still somewhat controversial but the ratio of EPA (eicosapentenoic acid) to DHA (docosahexenoic acid) should be 3:2. It is my understanding that omega 3:6 are of benefit, and although not harmful omega 9 has not been shown to be of benefit.
These neutriceutals are believed to provide the nutritional building blocks for cartilage repair. Beyond this, MSM seems to have anti-inflammatory properties and may act as an anti-oxidant (see below).
Anti-oxidants and Free Radical Scavengers
It is thought the the process of aging is a reflection of free radicals harming our joints, skin and brain through structural protein damage and inflammation. Perhaps supplementing with additional anti-oxidants can retard age-related change.
Anti-oxidants that are readily available include Vitamin C, Vitamin E, and SAMe. Denosyl (SAMe) is marketed for animals primarily for its effects in the liver.
Non-Steroidal Anti-Inflammatory Drugs (NSAIDs)
These medications act quickly by suppressing the inflammatory process which leads to both pain, and continued cartilage damage. While aspirin has been used to relieve joint pain, safer medications developed specifically for pet use have become the standard for joint pain management. Never use a human medication of any kind in a pet without specific instructions on how to do so from your veterinarian. Please note many of these products are toxic in cats. Never use more than one NSAID in a pet at one time, and when switching products ensure the withdrawal time between them is adequate. Commonly used NSAIDS used include: Carprofen (Rimadyl®, Vetprofen®),Deracoxib (Deramaxx®),Meloxicam (Metacam®), and Firocoxib (Previcox®).
Newer NSAIDS are often cox 2 selective, meaning that they only have influences on the prostaglandin enzymes responsible for the inflammatory process. "Good" prostaglandins are thought to be spared by these drugs, helping to maintain intestinal health and kidney circulation. The cox 2-inhibiting NSAIDS are thought to be safer. This is an oversimplification. There may be some other benefits to maintaining both types of prostaglandins, and even the type 2 selective products have been shown to have effects on the gut. All NSAIDS should be stopped in a patient exhibiting symptoms of vomiting or diarrhea, especially if dark-coloured.
Pre-treatment screening blood tests are still important before using an NSAID as a pre-existing kidney or liver condition may preclude their use. Monitoring tests typically are recommended every six months for pets on NSAIDs. Currently meloxicam is the only veterinary product approved for long-term management of arthritis in cats.
The corticosteroid hormones (prednisone, dexamethasone, lead to the relief of inflammatory conditions but for arthritis, other medications are usually superior. They have a number of side effects associated with longterm use including poor wound healing, slow hair growth, increased drinking and urination, muscle weakness and the development of diabetes. These products should not be abruptly halted.
Analgesics that are not Anti-inflammatory
A multimodal management approach involves the addition of pain relief. They do not have any anti- inflammatory benefits.Tramadol is a narcotic pain reliever similar in many ways to codeine. It is often compounded at a pharmacy. The use of tramadol in pets is off label, meaning that efficacy and safety studies have not yet been carried out in pets.
Gabapentin an anti-seizure drug, has been found to have benefits in reducing chronic pain associated with nerve pain. Again, the use is off label in pets, not having been studied. Note if discontinued, weaning is often necessary.
The use of these products seems to work alongside NSAIDS bringing relief to patients.
Adequan is an injectable cartilage component called polysulfated glycosaminoglycan (mostly chondroitin sulfate), derived from the windpipe cartilage of cattle. Adequan has numerous beneficial effects for the arthritis patient including the inhibition of harmful enzymes involving joint cartilage destruction, stimulation of cartilage repair, and increasing joint lubrication. Although given as an injection, it seems to concentrate where joints are inflamed. Usually requires twice weekly injections for 8 treatments, and then continued on an as needed basis. Approved for use in dogs, is is off label in cats, not having been studied.
In conclusion, the arthritic pet has a large menu of medications to select from and while proper medication is an important part of therapy, weight control and proper exercise should not be forgotten. For more specific recommendations for your individual patient, consult a veterinarian.
Adapted from VeterinaryPartner.com article by Wendy C. Brooks, DVM, DipABVP