Is flaxseed good for dogs?

Flaxseeds have a hard, shiny coat. Dogs rarely chew them, so whole seeds often appear unchanged in stools. Grinding breaks the coat and lets the body use the contents. Buy milled flaxseed or grind small batches in a coffee grinder.

Ground flaxseed goes rancid quickly. Store it in a sealed jar in the fridge and use it within a couple of weeks.

Ground flaxseed has about 530 calories per 100 g, mostly from fat and fiber. As a general guide, a quarter of a teaspoon suits a small dog, half a teaspoon a medium dog and up to a teaspoon a large dog, mixed into food. Start at the low end, as too much can cause loose stools and gas.

Flaxseed is rich in alpha-linolenic acid. The omega-3 fats that research has linked with skin, joint and heart health in dogs are EPA and DHA, found in fish oil. Dogs convert ALA to these only in small amounts. If your vet recommends omega-3 supplementation, ask which product and dose they suggest rather than relying on flax.

Flaxseed oil is pure fat, around 120 calories per tablespoon. Adding oil to a dog's diet increases calories quickly and can cause loose stools. Use it only if your vet advises, and measure carefully.

Raw, unripe flaxseed contains cyanogenic compounds. The mature seeds sold for food contain small amounts that are considered safe at normal serving sizes, which is another reason to keep portions small. Flax plants growing in fields or gardens should not be grazed.