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Tank, an English Bulldog, dressed as the Runaway Bride for the 21st Annual Tompkins Square Halloween Dog Parade in New York this month. Dressing up is fine, but keep dogs away from Halloween candy that may contain xylitol, a sugar substitute that can be dangerous or deadly to canines.

Keeping kids from overdosing on candy is every parent’s Halloween duty, but pet experts warn that the vigilance should extend to the furry members of the family as well.

That big bag of candy, gum and other treats hauled home from trick-or-treating can be dangerous -- or even deadly -- to dogs and some other pets, particularly because so many goodies now contain xylitol, a sugar substitute found in a growing number of sweets.

“Halloween is kind of the prime day for xylitol poisonings,” said Karen Leslie, executive director of The Pet Fund, a non-profit animal medical care agency. “This can be a very small exposure and a very big problem.”

The federal Food and Drug Administration earlier this year warned consumers about the dangers of xylitol poisoning in dogs and ferrets.

Just a single stick of gum could endanger a 10- to 20-pound dog, cautioned Eric Dunayer, an expert on xylitol poisoning and an associate professor of clinical sciences in the School of Veterinary Medicine at St. Matthew’s University, Grand Cayman. The amount of xylitol varies widely among foods, with those that contain less than 2 percent of the substance posing less risk.

In dogs, xylitol stimulates a massive release of insulin, causing a drop in blood sugar, which can lead to weakness, loss of coordination and seizures, Dunayer said. Xylitol also can lead to liver damage and death in rare cases. Symptoms can occur within 30 to 60 minutes of ingestion of xylitol and require immediate veterinary attention.

Reports of xylitol problems have been steadily rising for the past several years, said Tina Wismer, a veterinarian and medical director at the poison control center operated by the American Society for the Prevention of Cruelty to Animals, or ASPCA.

In 2010, the agency received more than 2,500 calls from owners frantic because their animals had ingested toxic treats. That's probably a fraction of the actual incidents, which are more likely to be reported to local vets.

“We tend to get a lot of gum calls,” Wismer said. “We can also find xylitol in other candies and mints.”

Visits to animal emergency clinics rise dramatically around Halloween and other candy-centric holidays, said Joan Dolance, a veterinarian and director of emergency care at the Animal Surgical & Emergency Center in West Los Angeles. She still recalls treating a Yorkie who ate an entire pack of gum found in his owner's purse.

"He was very sick, but he eventually recovered," she said.

Chocolate is a better-known poisoning culprit, but many pet owners still don't know about the dangers of xylitol, the experts added.

There is no antidote for xylitol poisoning, so veterinarians typically try to induce the pet to rid its system of as much of the dangerous product as possible. Activated charcoal, which is often used to treat other types of poisoning, may help, but some pets wind up hospitalized and on intravenous fluids for at least 24 hours, said Dolance.

The best treatment is prevention, of course, the experts say. Pet owners should keep xylitol-containing treats out of reach of animals. And they should check the ingredients on common foods such as pudding, Jell-O gelatin and baked goods, to make sure they're not sharing bites of xylitol-laced human food with their dogs.

With all of the chaos of parties and costumes and treats, pet owners should be especially cautious on Oct. 31, added Leslie, of the Pet Fund.

“Halloween is the one day we make sure they get nowhere near the candy," she said.

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