Osteoarthritis or Degenerative Arthritis in Dogs, Cats, Horses, Birds, and Other Pets
Is your pet having more difficulty getting up in the morning? Does he or she walk around still legged for the first 10 to 15 minutes in the morning to get warmed up? Is your pet limping especially on those cold, wet, rainy mornings? Does your pet limp around following that Frisbee session? If the answer to any of these questions is yes, then your pet is probably suffering from osteoarthritis.
Osteoarthritis is a degenerative joint disease (DJD) that is characterized by the wearing out of the articular cartilage (the cartilage located at joint surfaces), hypertrophy of the bone at the margins (enlargements of the end of the bones due to periostitis), and changes in the synovial membrane (the lining of the joints). Arthritis is characterized by stiffness and soreness which results in a decrease in motion and activity. Osteoarthritis may be caused by trauma, defective articular cartilage, joint instability, infectious processes, or congenital and developmental abnormalities.
Osteoarthritis can affect dogs, cats, horses, birds, and even guinea pigs. Some estimates place the incidence as high as 90% of geriatric cats having arthritic radiographic changes in their spine and joints. In some dogs, especially the larger and rapidly growing breeds, the incidence of osteoarthritis can approach 75 to 90% as well. If the individual lives long enough, virtually every animal will eventually be affected by degenerative joint disease. It is estimated that one in five adult dogs are affected by osteoarthritis at any given time.
When osteoarthritis is treated early, the disease progression may be slowed and the joint mobility increased resulting in an improved quality of life. The disease may be controlled but there is no cure and it must be managed as a chronic medical condition.
According to Darryl Millis DVM of the University of Tennessee you can expect a 70 to 80% response rate in any given treatment for arthritis. One of the first steps that should be taken to deal with arthritis is weight loss. Approximately 35% of adult dogs are overweight and of those that are middle-aged that percentage goes up to 50%. Excessive weight puts added stress on the joints which in turn contributes to the degenerative joint disease. When you are suffering with arthritis, it is far better to be on the skinny side.
Physical therapy is catching on and includes swimming, underwater treadmills, and passive range-of-motion exercises. Exercise is important to get the joints moving and increase their range-of-motion. Exercise should be conducted in such a way to maintain good muscle mass without causing further trauma to the joints. The pet needs to get both aerobic activity and strength training. Swimming is one of the most beneficial exercises because the water reduces the amount of weight on the affected joint thereby reducing stress on painful joints and happens to be one of the best aerobic activities available. Using hot or cold packs may also help with joint stiffness.
The addition of nutraceuticals such as supplements that contain omega-3 fatty acids may also be beneficial to joint health. It is believed that a diet high in omega-3 fatty acids may counter the development of inflammation-based illnesses such as arthritis, heart disease and cancer. Omega-3 fatty acids, also known as alpha linoleic acid or ALA, are commonly found in fish, walnuts, leafy vegetables, flaxseed, and hemp seed. Omega-3 fatty acids are acted upon by an enzyme called desaturase to manufacture Eicosapentaenoic acid (EPA) and Docosahexaenoic acid (DHA) which both affords anti-inflammatory and platelet inhibiting effects. It is estimated that less than 10% of omega-3 fatty acids will become EPA and DHA in the body. Fish oils already contain EPA and DHA thereby requiring no such conversion and are therefore considered to be a more beneficial supplement for trauma repair and arthritis than would omega-3 fatty acids from plant sources such as flaxseed.
Boswellia, also known as Indian frankincense, is an herbal supplement with analgesic, antirheumatic, and anti-inflammatory properties that may help with the pain and inflammation associated with arthritis. When a pet receives any herbal supplement you need to inform the veterinarian because interactions with other medications may occur.
If the pet is suffering chronic pain, especially when exhibiting lameness, nothing works better than non-steroidal anti-inflammatories (NSAIDs) for the immediate control of pain. Pets on NSAIDs should be monitored to make sure the dog doesn’t have or develop renal or liver dysfunction. Most veterinarians will want to monitor kidney and liver enzymes on a 3 to 6 month basis. Additional side effects of NSAIDs include: GI upset, stomach ulcers, and blood in the stool. Giving an NSAID with food will often help protect the GI tract. If one NSAID isn’t working well, then an additional type should be tried to see if it works better. Different NSAID’s have different pathways by which they inhibit inflammation or different chemical mediators of inflammation that they affect. Always try to use the lowest dose possible to control the pain or use only on a periodic basis, especially if nutraceuticals or chondroprotective agents control the pain the majority of the time. If the weather is going to be cold and damp, or if the pet is going to have some strenuous activity such as a long hike or hunt, start an NSAID the day before the activity and for a day or two afterward. NSAIDs are not routinely used in cats with some being very toxic and may easily be lethal in this species. When used in the cat, NSAID’s have an extremely small dose and safety range, if they can be used at all. Most NSAID’s have a warning label “not approved for use in the cat!”
Chondroprotective agents (drugs protecting the cartilage) include those medications containing glucosamine, chondroitin sulfate, and avocado/soybean unsaponifiables (ASU). These supplements are especially suitable for patients with osteoarthritis that are not suitable candidates for treatment with NSAIDs because of concurrent kidney, liver, or gastrointestinal problems. Past research on Cosequin® has shown it to have both a chondroprotective and an anti-inflammatory activity. Glucosamine and low-molecular-weight chondroitin sulfate will actually stimulate cartilage production and inhibit cartilage degradation. Many formulas of glucosamine and chondroitin are presently on the market but few products have been proven to be well absorbed thereby becoming bioavailable. The chondroitin must be of such a low-molecular-weight that it may be absorbed and utilized, by the patient.
Nutramax, the manufacturer of Cosequin® has recently released an additional supplement called ASU or Avocado soybean unsaponifiables that improves the overall health of chondrocytes (cartilage cells) in joint cartilage. ASU is currently being combined with glucosamine and chondroitin in their newest product termed Dasuquin® (for dogs and cats); and it too has anti-inflammatory activity will decrease the release of chemical and enzymatic mediators of inflammation from these same chondrocytes. Good, predictable analgesic responses have also been seen in cats with supplementation of glucosamine and chondroitin sulfate.
The University Of Maryland School Of Pharmacy conducted a study in the year 2000 that analyzed chondroitin sulfate products from various sources and concluded that 84% of the products they tested did not meet the claims on their labels. The chondroprotective and nutraceutical supplements are largely unregulated as compared to the pharmaceutical market.
Adequan® is a slow-acting, disease-modifying osteoarthritis agent, which may slow the progression of arthritis by modifying bonding to the cartilage, so this is a drug that should be used earlier rather than later. Adequan® is an especially good choice following joint surgery since it is an injectable and is especially useful in the interim period necessary for oral products to take affect.
Additional alternative medicines include acupuncture and electric stimulation.
Surgical management of osteoarthritis may be of benefit in certain cases by treating the underlying conformational defect or acting as a salvage procedure, such as a total hip replacement or a femoral head osteoectomy. These procedures eliminate abnormal bone to bone grinding.
There is no single effective treatment for arthritis. When dealing with arthritis, a multimodal approach is necessary. The right combination of treatments must be found for adequate pain control in each individual patient.
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