We’ve all heard about the dangers of certain sweeteners, but so far, they’ve all been dangers for humans. Our canine friends may be at risk, though. CBS News has reported a sweetener used in some types of sugarless gum could kill your dog.

Sam Caress and Jordan Pellet had a 2-year-old dog named Luna who got into some chewing gum made with sugar-substitute Zylitol. The dog started vomiting and they rushed her to the vet, but they weren’t quick enough.

“They gave us a phone call saying her kidney tests weren’t good, and that they were shutting down, and that we didn’t really have any other choice but to put her down,” Sam told CBS News.

Xylitol has been deemed safe for humans, but experts say it can be extremely dangerous for dogs. Dr. Ahna Brutlag, senior veterinary toxicologist at the Pet Poison hotline, told the Wall Street Journal that xylitol is one of the most dangerous food-related poisons her team deals with.

“There are still a lot of dog owners who have never heard of xylitol, nor do they understand that something this benign, an ordinary sweetener, could be toxic to pets,” she said.

Dr. Ashley Gallagher, from the Friendship Hospital for Animals in Washington D.C. told CBS vigilance on the part of owners is the key to saving dogs’ lives.

“You just have to be really careful because dogs are nosy little creatures and they are hungry all the time,” she said. “I know my dogs are, and they are just looking for a treat. So you really have to watch them.”

Gallagher recommends checking the labels of any products labeled “sugar-free” to be sure anything containing xylitol is kept away from pets. Sam and Jordan have learned the importance of checking for the little-known dog toxin.

“With a lot of things like candy and gum and peanut butter — we check all of them — if they have xylitol in them, we don’t buy them.”

The American Society for the Prevention of Cruelty to Animals’ (ASPCA) poison center said it received more than 3,700 xylitol related calls last year, with almost a dozen deaths, according to the Wall Street Journal. The Society has also released an information guide about xylitol for dog owners to keep pets safe.