Sugar-Free Can be Deadly for Dogs

Jennifer Coates, DVM
By Jennifer Coates, DVM on May 8, 2015

I’m not sure if it’s the time of year (the pre-bathing suit months?), but lately I’ve been hearing about an unusual number of cases of xylitol poisoning in dogs. Whatever is going on, it seems that a review of the danger that xylitol poses to our canine friends is in order.

Xylitol is a sugar substitute. It tastes sweet, but its chemical make-up means that it contains fewer calories than do sugar, corn syrup, and other traditional sweeteners. It also cannot be used as an energy source by oral bacteria, meaning it is less likely to promote the formation of cavities. Not surprisingly, these characteristics have led to xylitol being included in a long list of sugar-free products like gum, candy, baked goods, toothpaste, mouthwash, mints, and nutritional supplements.

Dogs and people both taste the sweetness of xylitol, but the species react very differently to it once it heads further down the gastrointestinal tract. People slowly absorb xylitol into the blood stream, while in dogs the process occurs at a MUCH faster rate. A dog’s body reacts to this influx of xylitol by secreting large amounts of insulin, which can quickly (often in less than 30 minutes) cause blood sugar levels to drop to potentially fatal levels. Symptoms of hypoglycemia (low blood sugar level) include:

  • lethargy
  • weakness
  • dullness or confusion
  • seizures

A dog who survives the initial effects of xylitol is still at risk. The chemical can damage the liver to such an extent that over the course of a few days, the dog may go into liver failure. Symptoms of acute liver failure typically involve a combination of the following:

  • loss of appetite
  • vomiting
  • diarrhea
  • abdominal pain
  • confusion
  • yellowing of the skin and mucous membranes

Some dogs also develop a condition called disseminated intravascular coagulation (DIC) that causes blood clots to form in dangerous places while paradoxically also leading to abnormal bleeding and bruising. Veterinarians sometimes say that DIC should actually stand for “death is coming,” which gives you an idea of its severity.

Treatment for xylitol poisoning involves inducing vomiting if the exposure has occurred within the last couple of hours and normalizing and supporting blood sugar levels until the risk of hypoglycemia passes. We don’t really know if hepatoprotectants like s-adenosylmethionine (SAM-e) are helpful in preventing the development of liver failure in dogs exposed to xylitol, but it doesn’t hurt to give it a try. Dogs should be monitored for the development of liver failure for at least three days after xylitol exposure and appropriate therapy initiated if necessary.

It doesn’t take much xylitol to cause problems in dogs. The equivalent of one or two pieces of sugar-free gum can be enough. Never give a food to a dog unless you are 100% sure that it does not contain xylitol. Dogs who may have gotten into xylitol should get to the veterinary clinic ASAP along with information regarding exactly what and how much they may have eaten.

If the signs of hypoglycemia develop before you can get to the vet’s office, dribble a small amount of a dissolved sugar solution, Karo syrup, or honey into the dog’s mouth, as long as you can do so safely.

Dr. Jennifer Coates

Image: Composite: TashaNatasha and phoelix / Shutterstock

Jennifer Coates, DVM


Jennifer Coates, DVM


Dr. Jennifer Coates is an accomplished veterinarian, writer, editor, and consultant with years of experience in the fields of veterinary...

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