By Dr. Julie Hunt
Xylitol is a sugar substitute that has become widely used in the U.S. over the past several years. It is popular with dieters and diabetics alike because it is sugar free, has zero calories, and helps prevent tooth decay. It is now commonly found in sugar-free gum, candy, and foods. In humans, xylitol is absorbed slowly and has little effect on blood sugar or insulin levels. But in the dog, xylitol is rapidly absorbed and causes a sudden spike in insulin, which in turn causes an acute profound drop in blood sugar that can be fatal.
It takes surprisingly little xylitol to cause toxic signs in dogs. The ASPCA Animal Poison Control Center reports that a 10 pound dog could have toxic effects from as little as a stick and a half of gum! As the amount of xylitol ingested increases, the effects get worse and can be irreversible. Think about the damage a pack of gum could cause, or worse, an entire “cup” of gum! You are probably wondering right now where you left your gum and whether your dog could get into it. That is the problem—unless pet owners are aware of the danger, it is all too easy for a “scavenger” dog to find and eat gum or sugar-free foods from a purse, car, backpack, or grocery bag left on the floor. Cows, goats, rabbits, and ferrets can have a similar reaction to xylitol. But luckily, cats are not known to develop xylitol toxicity.
The earliest sign of xylitol toxicity is vomiting, which then progresses to weakness, incoordination, collapse, and seizures. These signs can begin in as little as 30 minutes after ingestion or up to 12 hours later. At high xylitol doses in dogs, an even more serious and often irreversible reaction is destruction of liver tissue. This liver effect can take longer to show signs (8-12 hours) and surprisingly not all dogs who have liver damage show the earlier symptoms.
There is NO antidote for xylitol toxicity. Because it can be so rapidly absorbed, it is imperative to seek treatment by a veterinarian immediately. Treatment may involve inducing vomiting (depending on how long ago the xylitol was eaten), administering intravenous fluids containing dextrose (a form of sugar), and other supportive measures. Diagnosis is based on history of eating xylitol, typical symptoms, and blood test results showing low blood sugar, high liver enzymes, and other abnormalities. Because xylitol is so rapidly absorbed, there is no specific blood test for it and there is no use in administering activated charcoal. The outcome of xylitol toxicity is directly related to the amount ingested and the time elapsed before seeking veterinary emergency care. The outcome can be good for those dogs who eat low doses and get rapid treatment. Dogs that ingest high doses or whose owners delay emergency veterinary care can die.
The good news is that xylitol ingestion is preventable! Households with dogs should consider not keeping xylitol-containing foods in the house at all. If they choose to have those foods available, they must store them out of reach from the most curious canines. Recently, xylitol has even been found in some brands of peanut butter, which many dog owners use to hide pills or stuff Kongs. It is also in many toothpastes and mouthwashes including dog products. Of course, dog dental products do not have toxic levels of xylitol if they are used correctly. But if a dog accidentally finds and eats a whole tube of dog toothpaste, that could be potentially toxic depending on the dog’s size. The list of xylitol-containing products also includes breath mints, tooth whiteners, chewable vitamins, puddings and jello, yogurt, ice cream, and more.
The easiest way to prevent xylitol toxicity is to stop feeding human food to your dog, or at least read every ingredient list thoroughly.