Can Dogs Eat Marshmallows? Xylitol Risks and Holiday Safety

Marshmallows show up everywhere this time of year. They fill Halloween treat bags, float in mugs of hot cocoa, and melt into a golden layer on top of the Thanksgiving sweet potato casserole. So if your dog is staring at you while you snack, you might wonder whether sharing one is a big deal.

The short answer: a plain marshmallow is not toxic to dogs, but it is not a good treat either. And some marshmallows, especially sugar-free ones made with xylitol, can be truly dangerous. Here is what veterinary and pet health sources say, what to do if your dog sneaks some, and better treats to share instead.

Can Dogs Eat Marshmallows?

The American Kennel Club answers this one plainly: no. While not all marshmallows are toxic to dogs, the AKC says they certainly are not good for them. Marshmallows are made from sugar, corn syrup, gelatin, and vanilla extract, coated with cornstarch or confectioners’ sugar, and they contain very little, if any, nutritional value.

PetMD takes a similar view. It notes that the basic ingredients of a plain marshmallow are non-toxic for dogs, and that a little plain mini marshmallow once in a while is probably OK for an otherwise healthy dog. But PetMD still does not recommend marshmallows as a snack, because they are very high in sugar and offer dogs nothing they need.

So the honest answer is this: a single plain marshmallow that rolls off the counter is not usually an emergency, but marshmallows should never become a regular treat.

Why Marshmallows Are Bad for Dogs

1. Some contain xylitol

This is the biggest danger. Sugar-free marshmallows often contain xylitol, a sweetener that is safe for people but very bad for dogs, according to PetMD. Dr. Carly Fox of the Animal Medical Center in New York City told the AKC that a marshmallow made with xylitol is toxic to dogs and can be extremely harmful even in small quantities, causing dangerously low blood sugar, seizures, and even death if the dog is not treated properly. She also noted that xylitol has been shown to be toxic to the liver, even days after ingestion.

The U.S. Food and Drug Administration explains why. In dogs, xylitol is absorbed quickly and may trigger a powerful release of insulin, which can cause a rapid and profound drop in blood sugar within 10 to 60 minutes. Untreated, that drop can quickly become life-threatening. The FDA adds that xylitol may also be listed as birch sugar or wood sugar, so read labels carefully, especially on anything marketed as sugar-free or low sugar.

The good news is that, as PetMD points out, most marshmallows do not contain xylitol. But you should always check the ingredient list before assuming a bag is safe.

2. They are loaded with sugar

The AKC describes marshmallows as incredibly high in sugar and calories, which makes them especially risky for dogs with diabetes or weight problems. Even for healthy dogs, sugary treats can contribute to obesity, which can lead to diabetes due to insulin resistance. If your dog is already carrying a few extra pounds, our tips to help your dog lose weight are a better place to focus than the candy dish.

3. They can upset the stomach

Even marshmallows without xylitol can cause trouble when a dog eats too many. Dr. Fox and Dr. Lucas White, a veterinarian in Edmond, Oklahoma, told the AKC that eating too many can lead to gastrointestinal upset, including vomiting, lack of appetite, and diarrhea. The AKC adds that if those symptoms persist, your dog could also be at risk for pancreatitis.

4. They can be a choking hazard

PetMD notes that marshmallows can be a choking hazard for dogs. Soft, sticky foods that dogs gulp without chewing are worth keeping out of reach, especially for small dogs and enthusiastic eaters.

Watch Out for Seasonal Marshmallow Treats

Plain marshmallows are only part of the picture. Many fall and holiday treats pair marshmallows with ingredients that are much riskier for dogs.

• Hot cocoa with marshmallows: The ASPCA Animal Poison Control Center lists chocolate and cocoa among the foods to avoid, noting that baking chocolate and cocoa powder have the highest concentrations of the compounds that make chocolate toxic. Learn more in our guide on whether dogs can eat chocolate.
• S’mores and chocolate-covered marshmallows: PetMD advises checking the ingredient list for harmful ingredients like xylitol or chocolate if your dog steals a marshmallow treat.
• Sugar-free candy and baked goods: The ASPCA notes that xylitol is used in gum, candy, baked goods, and toothpaste, and that liver damage can occur within 12 to 24 hours of ingestion.
• Halloween candy bowls: Marshmallow candies often sit next to other sweets dogs should not have. Our article on whether dogs can eat candy corn covers the rest of the trick-or-treat haul.
• Sweet potato casserole: Plain cooked sweet potato can be a good dog treat, but the marshmallow, sugar, and butter topping is not. See can dogs eat sweet potatoes for safe serving tips.

What to Do If Your Dog Ate Marshmallows

1. Check the label. PetMD says to look first at the ingredient list for xylitol or chocolate. Look for birch sugar or wood sugar, too, which the FDA notes are other names for xylitol.
2. Estimate how many your dog ate. PetMD says one or two plain marshmallows will likely not cause serious harm. The AKC advises calling your veterinarian right away if your dog eats multiple marshmallows.
3. Act fast if xylitol is involved. The FDA advises taking your dog to your vet or an emergency animal hospital immediately if you think your dog has eaten xylitol. Because low blood sugar and other serious effects may not appear for up to 12 to 24 hours in some cases, your dog may need to be hospitalized for monitoring. Do not wait for symptoms.
4. Do not try to make your dog vomit on your own. The AKC notes that your vet may choose to induce vomiting if the marshmallows were eaten within the last couple of hours. That decision belongs to your vet.
5. Watch for warning signs. PetMD lists vomiting, diarrhea, loss of appetite, lethargy, stumbling or lack of coordination, and tremors or seizures as reasons to head to the vet. The FDA adds weakness and collapse as signs of xylitol poisoning.

If you are ever unsure, call your veterinarian, the Pet Poison Helpline at (855) 764-7661, or the ASPCA Animal Poison Control Center at (888) 426-4435 (a consultation fee may apply). PetMD says dogs that ate several marshmallows or have diabetes, obesity, or other health conditions may need to see the vet for treatment. It also advises never giving marshmallows to dogs that are small, young, or have a pancreas-related condition such as diabetes or pancreatitis.

Better Treats to Share Instead

If your dog deserves something sweet, PetMD suggests naturally sweet fruits that are safe for dogs, including apple, banana, blueberries, cantaloupe, raspberries, strawberries, and watermelon. The AKC also recommends high-quality dog treats or healthy snacks like carrots, green veggies, or blueberries.

• Apple slices with the core and seeds removed. Read our guide on whether dogs can eat apples for details.
• A few fresh blueberries, a small, low-mess treat.
• Treats made for dogs, including mallow-style dog treats that PetMD mentions as an alternative for campfire nights.

PetMD reminds owners that treats should make up only 10% of a dog’s overall diet, with the other 90% coming from a well-balanced dog food. If your dog has a health condition or eats a prescription diet, check with your vet before sharing any people food.

Frequently Asked Questions

Can a marshmallow kill a dog?

PetMD calls it highly unlikely, but possible, especially with marshmallows made with xylitol. Most marshmallows do not contain xylitol, so always check the label and call your vet right away if they do.

Can dogs eat mini marshmallows?

PetMD says a plain little mini marshmallow once in a while is probably OK for an otherwise healthy dog, but they should not be a regular treat. Small size does not change the sugar problem.

Can dogs eat sugar-free marshmallows?

No. PetMD warns that sugar-free marshmallows often contain xylitol, and the FDA explains that xylitol can cause a dangerous drop in blood sugar in dogs. Sugar-free does not mean dog-safe.

Can puppies eat marshmallows?

It is best not to give them any. PetMD advises never giving marshmallows to dogs that are small or young.

My dog ate a whole bag of marshmallows. What should I do?

Check the ingredients for xylitol or chocolate, then call your veterinarian. The AKC recommends calling your vet immediately if your dog eats multiple marshmallows, and PetMD says dogs that ate several may need veterinary treatment.

The Bottom Line

Dogs should not eat marshmallows. A single plain marshmallow is unlikely to hurt a healthy adult dog, but marshmallows are sugary, offer no nutrition, can upset the stomach, and can be a choking risk. Sugar-free marshmallows with xylitol are a real emergency. This Halloween and Thanksgiving, keep the candy bowl, cocoa, and casserole out of reach, share dog-safe treats instead, and call your vet or a pet poison hotline if your dog gets into something it should not.