As cats age, many will develop arthritis. In one study, it was determined that 90 percent of cats over the age of 12 show some radiographic signs of arthritis. However, young cats can suffer from this condition, as well.
“Reduced activity is the clearest sign that a cat has become arthritic,” explains Cailin Heinze, VMD, Assistant Professor of nutrition in the Department of Clinical Sciences at the Cummings School. “She’ll be less able to jump up on furniture, and she may have trouble getting into and out of her litter box.”
In some cases, the cat will start limping, or become more sedentary, and may indicate that she is in pain when her lower back or limbs are touched. The disorder and its discomfort tend to be more serious in overweight or obese cats, explains Dr. Heinze.
Joint Supplements for Cats
Unfortunately, osteoarthritis in cats is incurable. However, a number of treatment options are available to relieve the pain. Veterinarian-prescribed drugs can be effective for relatively mild, sporadic discomfort, while anti-inflammatory medications may be useful for long-term pain relief. And over the past two decades, a variety of over-the-counter dietary supplements called nutraceuticals − most notably glucosamine, chondroitin sulfate, and omega-3 fatty acids − have gained widespread popularity for their purported ability to ease the joint discomfort associated with feline arthritis.
In general, gastrointestinal upset tends to be the only side effect caused by glucosamine and chondroitin, which are typically combined in a single formulation. Dr. Heinze says that omega-3 fatty acids are useful dietary supplements because they have known anti-inflammatory effects and thus may be effective in easing joint discomfort.
“At least one study has shown that arthritic cats whose diets were supplemented with fish oil were, according to their owners, happier, could jump higher, and so forth, than arthritic cats who were given a placebo,” says Dr. Heinze. “Of course, the owners’ opinions were subjective, so I don’t know how much we can conclude from the study. But on the whole, the data — including data derived from studies on people, dogs, and rodents as well as cats — suggest that supplements containing fish oil offer some degree of benefit.”
In theory, it makes sense that glucosamine and chondroitin additives might also be of some value in improving the health of a cat’s joints. “These substances are basically sugars that are among the natural building blocks of the cartilage in those joints. So the idea is that, since osteoarthritis is caused by a breakdown of that cartilage over time, the remaining cartilage would theoretically be improved by supplementing the animal’s diet with these cartilage precursors. But glucosamine and chondroitin don’t do that, since damaged cartilage really can’t be rebuilt,” says Dr. Heinze. “The good news is that there are studies in other animals and anecdotal reports indicating that these substances may improve comfort in some situations – perhaps through an anti-inflammatory mechanism. And if you’re using a high-quality product from a reputable source – a product that actually contains what the supplier says it contains – then the safety level is pretty high.”
Regarding potential risks posed by the routine consumption of dietary supplements, Dr. Heinz says: “Glucosamine and chondroitin are generally safe, although they can possibly have gastrointestinal side effects. As for fish oil, lower doses of high-quality products are quite well tolerated, with mild gastrointestinal side effects being most common. With higher doses of fish oil, however, there is the possibility of bleeding problems, immunosuppression, and several other side effects. Because dietary supplements in general fall into a kind of gray area — they’re neither drugs nor foods —they don’t require FDA approval of their safety and efficacy before they can be marketed. This is really important for cat owners to know. While dietary supplements can be helpful, some are of poor quality, can contain contaminants, and can cause health problems.
“Discuss the situation with your veterinarian first to make sure that you select a high-quality product. And after feeding the supplement to your cat for a few months, if you see that a supplement is not helping, it doesn’t make any sense to continue.”