Xylitol Poisoning In Dogs

I was at lunch today when I saw Touloulou’s owner and asked how she was doing.

“I’m glad I ran into you because I had an epiphany the other day talking to my daughter. She said, ‘Touloulou isn’t eating my gum since school has been out.’ I asked what she meant and she said, ‘She gets my gum out of my school backpack and eats it. She hasn’t done that this summer.’”

“Is it sugarless gum?” I inquired.

“I don’t know but I’m pretty sure it is.”

We were having this conversation because Touloulou had recently been off her heartworm preventive and had gotten heartworms. As is routine, before starting heartworm treatment we performed routine screening laboratory tests and a chest X-ray to ensure that she was healthy enough to have a heartworm treatment.

She wasn’t. Had we gone forward with treatment not knowing about the liver problems that showed up, she might have died.

Of all the organs heartworm treatment is hard on, it is hardest on the liver.

Under ideal circumstances we would have performed a liver biopsy on Touloulou to have a pathologist evaluate the liver  microscopically and obtain a definitive diagnosis. However, as is common in the practice of veterinary medicine, additional tests just weren’t in the budget.

Instead we began symptomatic therapy with Denosyl, a neutraceutical that helps stressed livers perform better.

We also started her on an antibiotic, Clavamox  in case infection of the liver were a part of her problem.

Followup laboratory testing on Touloulou’s blood showed normal results, which means that one or both components of our therapy were working.

IF sugarless gum was the only cause of Touloulou’s liver abnormalities it represents an unusual presentation of Xylitol poisoning in dogs.

Xylitol has long been proven safe in people. Human users of Xylitol should have no worries under normal circumstances.

Xylitol is a naturally-occurring sweetener that is commonly used in sugar-free gum, beverages, pharmaceuticals, toothpastes and mouthwash, among other products. It is naturally found in many fruits and vegetables, but is commercially produced from birch and other hardwood trees, wood chips and corn cobs. Its public appeal is found in its greatly diminished calorie content when compared to sugar (sucrose) and its concomitant decrease in dental caries in children who chew gum.

Sugar-free gum is the most likely source of poisoning for dogs, but a recent report in the Journal of the American Veterinary Medical Association reported a dog poisoned by four large muffins sweetened with Xylitol.

The dose required to cause problems for a pet varies. There may be a factor of individual susceptibility as well. In any case, no dog should be allowed access to Xylitol-containing materials.

What should you do if you suspect your pet has eaten Xylitol? First, call your veterinarian or emergency hospital immediately. Experts there will help you determine whether your pet is at risk.

Signs of toxicity may begin with evidence of low blood sugar. Dogs who ingest Xylitol release massive amounts of insulin, because Xylitol is about four times sweeter than sugar, and the pancreas responds proportionately. Evidence of hypoglycemia includes weakness, tremors and seizures. Hypoglycemia does not occur in all victims, and occurs two to four days later in some victims.

Like most animal species, dogs can experience gastrointestinal signs: vomiting and diarrhea. But, unlike other animals, dogs who have ingested sufficient amounts of Xylitol, or individuals who are sufficiently sensitive to it, will experience liver damage and anemia. The damage to the liver may be mild or severe. Those who survive initially may show icterus (jaundice, yellowing of the eyes and skin), bilirubinuria (red urine which may be confused with blood in the urine, caused by breakdown of red blood cells in circulation), loss of appetite and extreme lethargy. Bleeding may occur as a result of damage to clotting factors in the body.

If these signs are not quickly addressed by your pet’s doctor, they can be immediately fatal, or leave your pet with liver damage that my shorten his life and require lifelong liver support.

Many patients do survive with aggressive therapy. An individual dog’s reaction to Xylitol may be idiosyncratic, with some dogs minimally affected, other dogs mortally affected, and every scenario in between.

If you use sugar-free gum, or other Xylitol-containing foods in your home, keep them securely out of reach of your dog. In a recent case at our hospital, a standard Poodle searched in his owner’s purse until she found the gum, and ate the whole pack. She presented with gastrointestinal signs, and the owner thought the gum might have obstructed the GI tract. Her initial GI signs, icterus and liver damage resolved sufficiently to bring her liver test results back into the normal range, though we don’t yet know how much the liver may have been permanently damaged and may shorten her life as a result.

What is unusual about Touloulou’s presentation is that at the time of the laboratory tests she was completely asymptomatic. Furthermore, no one in the family can recall any time that she was ill while eating the gum.

The absence of signs that rose to the point of being clinical may be an individual resistance to Xylitol effects on her part, or a low dosage, i.e., eating only a small amount of gum each time.

In any case, Touloulou’s “sister’s” backpack now hides her gum securely.


  1. My little chihuahua tack a pice Of strawberry which f from my plate she just put in her mouth and left because she didn’t like my question is she will have problems I have to take to the Vet. Tanks

  2. Dr. Randolph,
    I was giving my 45 lb BC mix a colostrum chewable tab everyday. I had been doing this for 3 – 4 years now. She is 6 or 7 years old. Last week, I read the label and I saw xylitol listed in the ingredients, right after sorbitol. I FREAKED! She has slight tremors in her front limbs at times and this has been apparent for a few years now, nothing major, but inexplicable. What can I do to reverse the damage? She gets annual blood work and so far, her liver enzymes have all been in normal ranges. Can you advise me? Thank you.

    • Touloulou had blood tests as a result of a positive heartworm test, as stated. Re-read the fifth paragraph. It’s unlikely that your pet has suffered liver damage from Xylitol ingestion. While we don’t recommend Xylitol for ANY pets, there does seem to be an idiosyncratic sensitivity in some individuals (meaning some tolerate it, some don’t). If there is NO increase in ALT, AST or Alkaline Phosphatase in your dog’s annual labwork I wouldn’t be concerned. If there is SLIGHT elevation, I would use Denosyl or Denamarin as a liver protective ingredient and retest after 30 days. An ultrasound evaluation of the liver would be a quick, easy and non-invasive way to evaluate overall size and consistency of the liver. Please write again if you have further questions and thank you for your readership of MyPetsDoctor.com.
      Dr. Randolph

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