Omega-3 Fatty Acids for Horses: An Overview

Just as certain vitamins and amino acids are essential to the diet, meaning they must be consumed in a feed source, so are certain fatty acids. Fatty acids are used as energy sources (acetate, propionate, butyrate) and as important functional components of cells (omega-6 and omega-3). Essential fatty acids (EFAs) for horses include omega-3 and omega-6.

Omega-3 fatty acids consist of alpha-linolenic acid (ALA), docosahexaenoic acid (DHA), and eicosapentaenoic acid (EPA). Flaxseed, chia seed, and soy and canola oils are good sources of ALA. Fatty acids contained in cold-water fish oils (e.g. menhaden oil) are rich in DHA and EPA as a result of the consumption of microalgae that synthesize these EFAs. What’s the difference between ALA and the other two? ALA must be metabolized into DHA or EPA, but the efficiency of converting ALA into DHA and EPA is fairly low. For this reason, consuming a direct source of DHA and EPA is often recommended.

Omega-3 fatty acids play an important role in the inflammatory process. EPA inhibits activity of the enzyme cyclooxygenase, which plays a role in symptoms of inflammation and pain. DHA is critical for proper vision, brain health, and nervous system function. Studies have shown potential benefit of omega-3 fatty acids for horses with lower airway disease (Nogradi, et al., 2015) and insect hypersensitivity (Friberg and Logas, 1999). In addition, research examining the supplementation of arthritic horses with omega-3 fatty acids suggests a reduction of inflammation, and could be useful nutritional support for joint inflammation (Manhart, et al., 2009).

According to Kathleen Crandell, Ph.D., a nutritionist for Kentucky Equine Research, “DHA and EPA have also shown support for cardiovascular health and reproductive processes.”

While scientists have not determined the ideal amount of omega-3 fatty acids that should be in the diet, the horse’s natural diet of fresh forage contains more omega-3s compared to a combination of grains and forages. To help balance the modern horse’s omega-3 intake, Kentucky Equine Research developed EO-3 from a sustainable source of menhaden fish oil in order to provide a direct source of DHA and EPA. In addition, EO-3 has been stabilized and deodorized to ensure effectiveness and palatability.

Contact a Kentucky Equine Research nutrition advisor for information on how EO-3 can help support your horse’s overall health.

Friberg, C., and Logas, D. 1999. Treatment of Culidcoides hypersensitive horses with high-dose n-3 fatty acids: A double blinded crossover study. Veterinary Dermatology. 10:117-122.

Manhart, D., B. Scott, P. Gibbs, J. Coverdale, E. Eller, C. Honnas, and D. Hood. 2009. Markers of inflammation in arthritic horses fed omega-3 fatty acids. The Professional Animal Scientist. 25(2):155-160.

National Institutes of Health. 2018. Omega-3 fatty acids. Accessed online.

National Research Council. 2007. Nutrient Requirements of Horses, 6th Ed. National Academies Press. Washington, D.C.

Nogradi, N., Couetil, L, Messick, J, Stochelski, M, and Burgess, J. 2015. Omega-3 fatty acid supplementation provides an additional benefit to a low-dust diet in the management of horses with chronic lower airway inflammatory disease. Journal of Veterinary Internal Medicine. 29(1):299-306.

Oregon State University Linus Pauling Institute. Undated. Essential fatty acids. Accessed online at: