Since its introduction in 2004, there have been increased reports of illness caused by ingestion of sugar free products containing the artificial sweetener, Xylitol. These primarily occur in dogs. Ferrets are reportedly sensitive to Xylitol but cats do not seem to be adversely affected.
Xylitol is a sugar alcohol sweetener made from the bark of the birch tree. In dogs, the sweetener triggers a large release of insulin causing hypoglycemia; an extremely low blood glucose(sugar). This will result in weakness, unsteadiness, altered responsiveness, dilated pupils and possibly seizures. If the dose of Xylitol is high enough the resulting long term hypoglycemia can lead to liver failure. Symptoms of liver failure can be lethargy, loss of appetite, vomiting and diarrhea.
Xylitol is a popular sweetener in sugar free foods, candy, and gum. Most pet exposure is from candy and gum. The amount of product eaten determines the degree of toxic injury. The toxic dose is 75-100 mg/kg. The quantity of Xylitol in a given product is unknown due to manufacturer's proprietary information and can range from 0.9 mg to 1000 mg. Typically, if Xylitol is listed as the first ingredient it is the most toxic. For example, Trident contains approx. 0.22 g Xylitol per piece of gum.
If known Xylitol exposure occurs, the first step is to call your veterinarian. We will be able to advise if induction of vomiting would be indicated. Depending on the dog's symptoms we may need to do blood testing or hospitalization with intravenous (IV) fluid support. If there are no symptoms within 8-12 hours of ingestion it is likely the dog will not have any toxic effects. If liver damage occurs, recommended treatment would be hospitalization on IV fluids and supportive care. With proper and timely care, the affected patient is likely to recover with no long term consequences.