When I first started my veterinary career more than 30 years ago, nutritional supplements were virtually unheard of in small animal medicine. Vitamins have had a long history of well-accepted use, but food- and plant-based “nutraceuticals” have only been an accepted part of most veterinary practices in the last 15 years. One of the most popular supplements in both animal and human health today is fish oil, also known as omega 3 fatty acids. It is commonly prescribed by veterinarians for a wide variety of clinical conditions, but how beneficial is it, and are there any potential adverse effects from its use?
So what’s so great about fish oil anyway? Why is it one of the most popular dietary supplements for animals and people alike, generating over a billion dollars in sales last year? Certain types of fish and other marine animals, especially colder water species such as salmon, have high levels polyunsaturated (omega 3) fatty acids in their flesh. Research has shown that these fats have an anti-inflammatory effect in the body, and have been touted as being able to reduce the incidence of heart disease in humans. Veterinarians most commonly prescribe omega 3 supplements to help treat allergic skin cases in dogs and cats, but some studies have suggested that they may have benefit in dementia and cognitive decline in older pets as well. Other potential uses include arthritis and even cancer. While there there is a considerable amount of research in both the animal and human fields, the results are definitely mixed, and certainly not definitive. There is good evidence that overuse of fish oils can cause problems with blood clotting and vitamin E deficiency. So with a lack of definitive clinical benefit, and a possibility of adverse effects, why use fish oil supplements at all?
There is certainly no debate that omega 3s are a vitally important dietary nutrient. One of the issues with omega 3s, though, is their instability when exposed to heat and high pressure, conditions common in the manufacture of commercial dog and cat foods. This can result in levels in the diet that are insufficient for moderating inflammatory conditions such as allergic skin disease and arthritis. One type of omega 3 known as DHA is thought to be important for brain function. It is possible that a deficiency of this essential nutrient may result in early onset senility in older animals or delayed brain development in puppies and kittens.
So if most commercial diets are deficient in omega 3 fatty acids, it seems logical to supplement most dog and cat diets. There are, however, some important things to consider. Because polyunsaturated fatty acids are so fragile, some supplement products are degraded…actually rancid, because of improper handling or storage. It can be difficult to know if you are using a poor quality oil, but if the product smells fishy, throw it away! Giving you pet a rancid fish oil product is definitely worse than no supplementation at all. The other issue is the source and possible toxins in the product. Heavy metals accumulate in the bodies of some fish, so I recommend getting oils that are sourced from less polluted areas of world such as Alaska or the arctic regions of Norway. Krill oil, which comes from a tiny crustacean harvested in Antarctic waters, is another good source.
Because the quality and proper dosage of supplements are often uncertain, I always recommend my patients get their important nutrients mainly from their food. This is just another example where nature knows best. I don’t believe that feeding commercial pet foods alone are adequate in providing all the nutrients that our pets need to be as healthy or to live as long as they should. (See my article, The Kibble Conundrum, http://animalkindvet.com/kibble-conundrum.) I frequently recommend adding to my patients’ diets fresh unprocessed foods that are naturally high in omega 3s such as grass-fed beef, lamb and pasture-raised chicken eggs. Cultured milk products such as yogurt or kefir from our local cows and goats are also excellent. Broths made from grass-fed beef bones are great for convalescing or geriatric pets. Animals that are raised in large commercial feedlots and factory farms are mainly fed grains, which results in food products that have very little omega 3s, and invariably contain unhealthy antibiotic and pesticide residues.
The bottom line is, yes, I do recommend using omega 3 supplements in some pet’s diets depending on the situation, but only using products with which I am confident of their quality and purity. (Here’s a tip: never buy a fish oil supplement for your pet our yourself from a big box store.) Certainly more research needs to be done to determine the efficacy of supplementation with fish oils. Buy the best quality commercial pet food you can afford—it really does make a difference in your pet’s health—and consider adding fresh, omega 3-rich whole foods to your pet’s food, or making your own diets. Dr. Karen Becker’ s book, Real Food for Healthy Dogs and Cats is a great guide for those interested in making pet foods at home.
Dr. Judkins is the owner of AnimalKind Holistic Veterinary Clinic in Historic Jacksonville.