A reader recently asked us whether MCT oil would be better than the fat in her dog's homemade recipe. She had been reading about C8, C10, and C12, and it was a very good question. It led us to add MCT oil to our feeding calculator. Here is what those labels mean, what the research in dogs shows, and how to use MCT oil safely.
What MCT oil is
MCT stands for medium-chain triglycerides. Most fats in food are long-chain fats. Medium-chain fats are shorter, so a dog's body handles them differently: they travel straight to the liver, which can turn them into ketones quickly. Ketones are an alternative fuel for the brain.
This matters for dogs in particular. Dogs are harder to get into ketosis than people are. Even on a very low carbohydrate diet, many dogs make only small amounts of ketones. MCT oil is one of the most reliable ways to raise them.
C8, C10 and C12: what the numbers mean
The number is how many carbon atoms are in the fat's chain. Shorter chains turn into ketones faster.
- C8 (caprylic acid): the most ketogenic. It raises ketones in dogs most reliably.
- C10 (capric acid): raises ketones less than C8. Laboratory research suggests it may also calm overactive nerve signaling directly, which may matter for seizures.
- C12 (lauric acid): labeled medium-chain, but a dog's body handles it much like an ordinary fat, so it produces few ketones. It is the main fat in coconut oil.
That is why coconut oil is not a substitute for MCT oil. At the KetoPet Sanctuary (2014 to 2017) we used MCT oil made only of C8 and C10.
What the research in dogs shows
Seizures. In a 2015 trial, dogs with idiopathic epilepsy had fewer seizures on a diet enriched with MCT than on a control diet. A larger 2020 trial added MCT oil, at about 9% of daily calories, to the usual food of 28 dogs who were already on seizure medication. Over three months on MCT oil, compared with three months on a control oil, 2 dogs had no seizures, 3 had their seizures cut by half or more, 12 had a smaller reduction, and 11 had no improvement.
So MCT oil helps some dogs, not all, and it is used alongside medication, not instead of it.
Never stop or lower seizure medication on your own; change it slowly with your veterinarian.
Memory and learning in older dogs. In a 2010 study, older Beagles fed a diet with added MCT did better on memory and learning tests than dogs on a control diet.
Other conditions. For allergies, mobility or cancer, there is little research on MCT oil itself, so we can't say it helps.
How to use MCT oil safely
- Start small. Begin with about a quarter of the full amount and build up over about two weeks. Adding it too fast often causes loose stools or vomiting. If that happens, go back a step for a few days.
- Swap, don't just add. MCT oil is fat, so it has calories. Use it in place of some of your dog's other fat, or your dog may gain weight.
- Pancreatitis. If your dog has ever had pancreatitis, talk to your veterinarian before adding MCT oil.
- Read the label. Choose an oil that lists only C8 and C10 (caprylic and capric acid). Avoid blends that are mostly C12, and avoid flavored oils or powders with sweeteners. Xylitol is poisonous to dogs.
Try it in our calculator. Our free feeding calculator now has an "Add MCT oil (C8 and C10)" option for homemade recipes. Tick the box before choosing your main fat. The recipe shows how much MCT oil to use, reduces the other fat to match, and explains how to build up slowly.
Where to go next
Our free guide, What's Really in the Bowl, explains how to read a dog food label and find the carbohydrate. If you'd like to talk with other families, join the KetoPet Support group on Facebook.
Sources
- Law TH, Davies ES, Pan Y, et al. A randomised trial of a medium-chain TAG diet as treatment for dogs with idiopathic epilepsy. British Journal of Nutrition 2015;114:1438–1447.
- Berk BA, Law TH, Packer RMA, et al. A multicenter randomized controlled trial of medium-chain triglyceride dietary supplementation on epilepsy in dogs. Journal of Veterinary Internal Medicine 2020;34:1248–1259.
- Pan Y, Larson B, Araujo JA, et al. Dietary supplementation with medium-chain TAG has long-lasting cognition-enhancing effects in aged dogs. British Journal of Nutrition 2010;103:1746–1754.
- Chang P, Augustin K, Boddum K, et al. Seizure control by decanoic acid through direct AMPA receptor inhibition. Brain 2016;139:431–443.
This article is general information, not veterinary advice.