For many mischievous pets, the kitchen table is never out of bounds and it's hard to resist the pleading eyes of a pooch begging for a sweet treat.

But what's safe for humans can be toxic for dogs. A recent study warns about the dangers of xylitol, a commonly used sugar substitute found in some sugar-free candy, gum and baked goods.

"Dogs are the primary victims of xylitol because dogs are the type of animal that will jump up on the counter and steal a cupcake or steal their owner's pack of gum out of their purse," said Dr. Louise Murray of the ASPCA.

Cases of xylitol poisoning are on the rise. The ASPCA's poison control center managed 170 cases of xylitol poisoning in 2005, twice the number of cases in 2004. This years' number suggests the upward trend continues. Even small amounts of xylitol can be lethal.

"You can see symptoms when a dog eats xylitol in as soon as 30 minutes," said Dr. Murray. "They'll begin to vomit, have tremors, some of the dogs will have seizures // and actually their liver will begin to fail."

Kelly Philips takes special care with her bulldog, Winston.

"Just make sure that you know if you're done eating or if you're just hanging out and there's stuff on the coffee table that it's quickly removed, so he can't get into it," she said.

As the trick or treating begins, an extra dose of caution is required for man and his best friend.