Can Dogs Eat Mashed Potatoes? Plain Potato vs Butter, Milk, Garlic and Onion
Plain cooked potato is generally safe for dogs in small amounts, but butter, garlic and onion are not. Here is what to skip, how much is fine and when to call a vet.
Dogs can eat a small amount of plain mashed potato made from fully cooked potato with nothing added. The problem is the usual recipe: onion, garlic, large amounts of butter, cream and salt can upset a dog’s stomach or be harmful. Holiday and restaurant mashed potatoes are best kept away from the dog, and the safest treat is a spoonful of plain, cooled, cooked potato.
Plain potato is the safe starting point
Cooked white or sweet potato is not toxic to dogs. Boiled or baked potato with no seasoning is mostly starch, and it can be a bland treat. It is not a balanced food, though, and it adds calories. Treats and extras should stay a small part of a dog’s daily intake, and the exact amount depends on the dog’s size and health. Your veterinarian can give a number for your dog.
Raw potato and green potato skins are a different matter. They contain solanine, a compound that can cause stomach upset and, in larger amounts, more serious signs. Always cook potatoes thoroughly, peel them if they have green patches and never feed raw potato or potato plants.
What makes holiday mashed potatoes risky
Onion and garlic
Onions, garlic, chives, leeks and shallots belong to the allium family. They can damage a dog’s red blood cells and lead to anemia. Cooked, raw and powdered forms are all a concern, and garlic or onion powder can be strong. Many gravies, seasoning blends and restaurant mash include them, so a dog should not eat mashed potatoes unless you know exactly what went in.
Butter, cream and milk
Butter and cream are high in fat. A rich serving can bring on vomiting or diarrhea, and in some dogs a sudden fatty meal can trigger pancreatitis, a painful inflammation of the pancreas that needs veterinary care. Many dogs also have trouble digesting lactose, the sugar in milk, which can cause gas and loose stool.
Salt and seasonings
Salty food is not good for dogs, and large amounts can be harmful. Pepper, herbs and spice blends can also upset the stomach. Leftover potatoes served with gravy, bacon or cheese add more salt and fat.
Xylitol and other additives
Mashed potato made from a box or sold prepared may contain flavorings or additives you do not recognize. Read the label, and never share any food containing xylitol, a sweetener that is dangerous to dogs.
How to serve potato to a dog
- Peel the potato and remove any green areas.
- Boil or bake it until fully soft with no salt, oil, butter or seasoning.
- Mash and let it cool.
- Offer a spoonful or two for a small dog, or a few spoonfuls for a larger one, as an occasional treat.
- Watch for vomiting, diarrhea or itching afterward, and stop if you see any.
Introduce any new food gradually. A dog with diabetes, a weight problem, pancreatitis or a sensitive stomach should only get extras that your veterinarian has approved.
Mashed potatoes at holiday dinners
Holiday meals are a common time for dogs to eat things they should not. Keep the dog away from the table, ask guests not to share plates, and set aside a small portion of plain food for the dog before you add butter and seasoning. For other plates, see our guide to what dogs can eat from a turkey dinner, why holiday ham is a poor treat and the difference between plain pumpkin and pie filling.
When to call the vet
Call your veterinarian if your dog ate mashed potatoes with onion or garlic, a large amount of buttery food, or anything and shows vomiting, diarrhea, weakness, pale gums, belly pain or a lack of appetite. Signs from onion or garlic can appear a day or more after eating. If your dog may have eaten a toxic food, contact an emergency vet or the ASPCA Animal Poison Control Center. Do not try to make your dog vomit unless a professional tells you to.
Quick answers
Can dogs eat sweet potato mash?
Plain, cooked and cooled sweet potato is generally fine in small portions. The same rules apply: no butter, sugar, spices or marshmallow topping.
Can puppies eat mashed potatoes?
Puppies have sensitive stomachs. Ask your veterinarian before offering anything besides their regular food.
Are potato chips or fries okay?
No. They are salty and greasy, and they can upset a dog’s stomach. See the guide on which human foods are safe for dogs for a quick check.
What if my dog ate a spoonful of regular mashed potato?
A lick or a spoonful of mash with a little butter usually causes nothing more than mild stomach upset in a healthy dog. If it contained onion or garlic, or your dog is small or has health problems, call your vet.
