Can Dogs Eat Mashed Potatoes or Sweet Potatoes? Thanksgiving Sides Explained
US Thanksgiving is Thursday 26 November 2026, and the side dishes are where most dogs get into trouble. Not because potatoes are poisonous, but because of what goes into them.
Plain potatoes: yes, in small amounts
The American Kennel Club says dogs can eat plain white potatoes if they are fully cooked, such as boiled or baked, with nothing added. Raw potatoes, green patches and sprouts contain solanine, a natural toxin, so never feed raw or green potato or the peelings from the compost bin. Cooking lowers the solanine level.
Sweet potatoes: yes, cooked and plain
Cooked, peeled sweet potato is a common dog treat and a source of fibre. The AKC advises never feeding it raw, because raw sweet potato is hard to chew and digest and can cause a blockage. Keep portions small: sweet potato is starchy, so go carefully with dogs that are overweight or diabetic.
The Thanksgiving versions are the problem
- Butter, cream and gravy: rich, fatty food can cause vomiting, diarrhoea and, in some dogs, pancreatitis
- Garlic and onion: common in mash, stuffing and gravy; onion and garlic in all forms (powder, fried, cooked) can damage dogs' red blood cells
- Salt: a lot of salt is unhealthy, especially for small dogs
- Marshmallows and sugar: the sweet potato casserole topping has nothing a dog needs, and sugar-free versions can contain xylitol, which is an emergency
- Nutmeg and other spices: nutmeg in large amounts can upset the stomach and nervous system
- Cheese and bacon toppings: salty and fatty
How much plain potato is OK?
A common rule from vets is that treats should be no more than about 10% of a dog's daily calories. In practice that means a tablespoon or two of plain mash for a small dog, and a few cubes for a large dog. Set some aside before you add the butter and seasoning.
My dog ate the mashed potatoes. What now?
- Work out what was in the dish and roughly how much was eaten
- If it contained onion, garlic, xylitol, raisins or a lot of fat, call your vet or a pet poison line now. Don't wait for symptoms
- Watch for vomiting, diarrhoea, a painful belly, lethargy or not eating over the next 24-48 hours
- Don't make your dog vomit unless a vet tells you to
US: ASPCA Animal Poison Control +1 888-426-4435 or Pet Poison Helpline +1 855-764-7661 (a fee may apply).
Quick FAQ
Can dogs eat mashed potatoes? Only plain ones. Mash made with butter, milk, salt, garlic or onion isn't a good idea, so save a spoonful of plain boiled potato instead.
Can dogs eat sweet potato casserole? No. The sugar, butter, marshmallows and spices make it a poor choice. Plain cooked sweet potato is fine.
Can dogs eat potato skins? It's best not to. Peel can hold more solanine, especially if it has turned green.
Can dogs eat French fries or potato chips? They aren't toxic, but they are salty and fatty. Skip them.
More holiday food guides: Thanksgiving pet safety, can dogs eat turkey and can dogs eat pumpkin.
Sources: AKC: Can dogs eat potatoes?; AKC: Can dogs eat sweet potatoes?; ASPCA: people foods to avoid feeding your pets.