The Animal Poison Control Center of the American Society for the Prevention of Cruelty to Animals has managed a substantially increased number of cases involving xylitol poisoning in dogs. Found in sugar-free chewing gum, candy, and baked goods, xylitol is a sweetener that can cause serious and sometimes life-threatening problems for pets.

The center managed more than 170 cases of xylitol poisoning in 2005, up from approximately 70 in 2004, said Dana Farbman, a certified veterinary technician and spokesperson for the center. As of August, the center had managed nearly 114 cases in 2006.  An increase in availability of xylitol-containing products may be one reason for the rise in cases, Farbman said.

While it was previously thought that only large concentrations of xylitol could cause problems in dogs, lesser amounts of the sweetener may also be harmful, the center reported.    "Our concern used to be mainly with products that contain xylitol as one of the first ingredients," said Dr. Eric Dunayer, who specializes in toxicology at the center. "However, we have begun to see problems developing from ingestions of products with lesser amounts of this sweetener." Dr. Dunayer said that with smaller concentrations of xylitol, the onset of clinical signs could be delayed as much as 12 hours after ingestion.

According to Dr. Dunayer, dogs ingesting substantial amounts of items sweetened with xylitol could develop a sudden drop in blood sugar, resulting in depression, loss of coordination, and seizures. "These signs can develop quite rapidly, at times less than 30 minutes after ingestion of the product. Therefore, it is crucial that pet owners seek veterinary treatment immediately," Dr. Dunayer said. He also said that there appears to be a strong link between xylitol ingestions and the development of liver failure in dogs.