flaxseed for horses

The scoop on flaxseed for horses!

  • Should you be feeding your horse flaxseed? Sure? Maybe? It depends. It might work for your horse, and you might need to make another adjustment to his diet if that’s the case. You will also need to consider if you want to grind the flaxseed yourself, or if it’s easier to find stabilized flaxseed for horses at the feed store.

three black feed tubs

There’s not a lot of bulk to flax, so it’s easy to add to meals.

Flaxseed, also known as linseed, are tiny seeds from the flax plant.

  • Flax is one of the oldest known fiber plants, which actually have lovely purple flowers to boot. The seeds are rich in omega fatty acids, about 40%. There’s about 30% fiber, much more than brans, and about 20% protein.

  • This can be ideal for horses, as flax is a natural anti-inflammatory agent with those amazing omega fatty acids. And a nice shine maker, too!

  • Flax fed whole quickly turns slimy. There’s an aspect to the flax coating that gets jelly-like when wet or exposed to saliva. Some horses may not like this.

  • Here’s the second kicker – they need to be eaten within about 15 minutes of grinding, as they become rancid quite fast. The alternative is to find a commercially available stabilized flax that is already ground. Same benefit, infinitely longer shelf life.

flaxseeds on a table with a spoon

A few more notes on flax. There is some evidence that horses can chew the seeds enough to get the benefits of those omega fatty acids, but the standard practice is to use a ground version.

  • There’s also a lot of information about how much your horse can eat per day, some sources say four ounces, some sources say an entire pound. Your veterinarian or equine nutritionist can help you figure out the best quantity for your horse. Generally speaking – four to eight ounces a day is just fine.

  • Don’t boil the flax, either, this “kills” the helpful omega fatty acids. Also, know that flax is very high in phosphorus, so balance this out with calcium from forage or a supplement. Again, your veterinarian or equine nutritionist can help.

When you are adding flax to your horse’s diet, know that the addition of water can help a chemical reaction create cyanide in the flax. But do not panic!

  • Let’s keep this simple – ground flax plus air or water creates cyanide. More exposure leads to more cyanide. This is why the 15 minute “rule” exists for fresh ground flax.

  • BUT – whole flax put in boiling water kills the cyanide. And strangely, whole flax put in cold water and brought to a boil releases SOME cyanide.

  • Stabilized flax from a reputable supplier is treated with heat to get rid of any cyanide.

  • How dangerous is the cyanide? Your horse would have to eat literal POUNDS of fresh ground flax or cold water flax to even remotely come close to toxic levels. Additionally, through science, there are some low cyanide forms of flax being developed and grown. Yeah science!

  • But what if your horse breaks into the feed room and eats a bin of WHOLE flax? No worries about the cyanide, whole flax hits the stomach and those digestive acids denature any proteins that make cyanide. HOWEVER – you will have a horse with possible colic and possible laminitis – just as if he gorged on grain.

What’s the best way to feed flaxseed to horses? Whole or fresh ground or stabilized?


  • The best way is for you to decide. I’m at a boarding barn, and the horses are fed rations 4 times a day. There’s a significant inconvenience to fresh grinding flax 4 times a day. So I buy a bag of stabilized from the feed store. It stays fresh, any and all cyanide possibilities are gone, and it’s easy to scoop and go.

The bonus is that flaxseed is delicious, so it’s likely going to be very easy to convince your horse to chow down.