NORTH GRAFTON (CBS) – The Kozaczka kids showered one of their dogs, Jack, with love, as they anxiously waited to visit their other pup, Rosie, in the animal hospital. “We were thinking the worst brain tumor or something like that,” said Jill Kozaczka.

Rosie is a two-and-half year old Bull Mastiff who within minutes Wednesday night went from playing, to becoming limp, to suffering a seizure.

“I was just shocked because she’s never had any health problems and it was just so sudden,” said Kozaczka.

The family rushed Rosie to the Foster Hospital for Small Animals at Cummings Veterinary Medical Center at Tufts University. The veterinarians figured out she had eaten a container of gum with Xylitol. It’s an issue the veterinarians are seeing more of.

“It’s one we see more and more of, the more Xylitol is out there,” said Dr. Elizabeth Rozanski, emergency and critical care veterinarian. “We also see it in peanut butter sometimes, and any sugar replacers so it can be in lots of places people don’t look at.”

In dogs the sugar substitute acts like a fake form of insulin.

“It makes their blood sugar fall very low they can have seizures with that and liver failure so it is something that can be really, really deadly,” said Dr. Rozanski.

Thirty-nine pieces of gum sent a 120 pound Rosie to the veterinary E.R. and I.C.U.

“You always hear chocolate, things like that, we keep the remotes away,” said Kozaczka.

Kozaczka, who is a teacher, wants her lesson to be one for others.

“If we had waited any longer it would have been fatal,” said Kozaczka.

Fortunately that’s not the case. The family took a picture when they visited Rosie shortly after we talked with them. It showed three kids and one pup who looks ready to go home.