The board-certified veterinary nutritionists at Tufts are commonly asked by clients whether they should be adding fish oil to their cats’ daily food regimens because they’ve heard there are benefits to the oil’s omega-3 fatty aids. The answer: maybe. There are some diseases for which research suggests fish oils can augment treatment.
Arthritis. Much of the pain and decreased mobility of arthritis results from inflammation of the joints. But two types of omega-3 fatty aids in fish oil — EPA and DHA (eicosapentaenoic acid and docosahexaenoic acid) — can help take down joint inflammation and thereby allow a cat to move around more comfortably. (Note: If your arthritic cat is overweight, getting him down to a nice trim weight will do more good for easing his joint pain than fish oil supplements, says Tufts veterinary nutritionist Deborah Linder, DVM.)
Heart disease. Like arthritis, heart failure is associated with inflammation, and fish oil can help take down the internal swelling. Additionally, fish oil may help attenuate the muscle loss (cachexia) that goes hand-in-hand with heart failure. It may even help reduce abnormal heart rhythms (arrhythmias).
Kidney disease. In some studies, it has been shown that dogs with kidney disease who were supplemented with omega-3s had real clinical benefit, such as less protein in their urine. It is too soon to know if that’s true for cats — evidence remains scant, and we don’t even know with certainty the mechanism by which omega-3s might help an animal’s failing kidneys. However, there is some evidence to suggest that cats with kidney disease may live long-er when fed a diet with higher levels of EPA that can be obtained with a prescription from a veterinarian.
How much, what kind?
You should not go to a store and simp-ly pull a fish oil supplement off the shelf that looks good to you. This is an instance in which you really should first have a discussion with your cat’s doctor. You have to make sure your pet gets the correct dose for his weight (there are all different doses depending on the condition) and that the vet recommends a brand with good quality control so you know that the contents of the supplement are what the label says they are.
When your vet prescribes a particular dose, make sure you know whether it’s for total omega-3 fatty acids or just EPA and DHA. It’s easy to come away confused. For example, some brands may say 1,000 milligrams fish oil per capsule, but the EPA and DHA is only 300 milligrams of that total.
Furthermore, fish oil supplements are not safe for every cat. If your pet has a gastrointestinal issue or a bleeding disorder, for instance, they may be contraindicated. (Fish oil “thins” the blood, which is why supplements may not be right for a cat with a bleed-
ing disorder.)
Finally, when you first start administering the fish oil, be on the lookout for loose stools or diarrhea. That’s usually the first side effect, Dr. Linder says. “We typically start at a lower dose and gradually work up to test for tolerance.”
Finally, bear in mind that fish oil is never going to be a cure-all. For serious diseases like the ones mentioned above, prescription drugs will usually be necessary. The fish oil should be viewed as a potential adjunctive therapy rather than a mainstay of treatment.
