Omega-3 fatty acids — primarily alpha-linolenic acid (ALA) from plant sources and EPA and DHA from marine sources — are powerful anti-inflammatory compounds that support joint health, skin and coat quality, immune regulation, and respiratory function in horses. Fresh pasture grass is naturally rich in ALA, which is why pastured horses often have glossier coats and fewer inflammatory issues than horses on hay-only diets. The modern equine diet tends to be heavily skewed toward omega-6 fatty acids (from grains and vegetable oils), which promote inflammation when the omega-6 to omega-3 ratio gets too high. Restoring a healthier ratio by increasing omega-3 intake can help manage chronic low-grade inflammation that contributes to joint stiffness, skin conditions like sweet itch, and airway hypersensitivity. For horses with arthritis, laminitis recovery, or allergic skin conditions, omega-3 supplementation has shown measurable benefits in research studies. Flaxseed (linseed) is the most common omega-3 supplement for horses, providing concentrated ALA, while fish oil provides EPA and DHA for horses that need stronger anti-inflammatory support.
A horse on fresh pasture naturally gets a good omega-3 supply, but hay-fed horses typically need supplementation. About 60 to 120 milliliters of flaxseed oil per day — roughly a quarter to half a cup — provides a meaningful omega-3 boost for a 500kg horse. Alternatively, 100 to 200 grams of ground flaxseed daily is effective. A small handful of hemp seeds (about 30g) as a treat also contributes, though not enough alone to correct a significant imbalance.
0.74% of daily nutrient intake
Omega-3 Fatty Acids makes up 0.74% of your horse's total daily nutritional requirements by weight. That's a tiny amount — but it matters.
Dull, dry, or flaky coat and skin, increased susceptibility to skin conditions and allergies, stiff joints especially in older horses, slow recovery from exercise or injury, and a generally pro-inflammatory state that can worsen conditions like arthritis, laminitis, and recurrent airway obstruction.
Excessive omega-3 supplementation can cause loose stools due to the high fat content, and very large amounts of fish oil may give manure an unpleasant odor. Extremely high doses could theoretically impair blood clotting, but this is not a practical concern at normal supplementation levels.
| Life Stage | Size | Min | Max | Unit | Notes |
|---|---|---|---|---|---|
| Adult | — | 10 | 30 | g | No NRC requirement established. Approximate target based on research for anti-inflammatory benefits. Fresh pasture provides 10-20g ALA daily; hay-fed horses benefit from supplementation. |
| Working / Active | — | 15 | 40 | g | Working horses benefit from higher omega-3 for joint protection and exercise recovery. Flaxseed oil or ground flaxseed are the most practical sources. |
Source: general veterinary consensus, research literature
