Xylitol is a sugar alcohol found in many sugarless candies and gums, baked goodies, cereals, and drinks. It can be VERY toxic to our pet patients. One of the most significant side effects seen with xylitol ingestion is HYPOGLYCEMIA. It has also been suggested as possible cause of acute LIVER FAILURE, which can lead to coagulopathy, disseminated intravascular coagulation (DIC), and death.
Toxic doses: Dogs which ingest more than 0.1g/kg of xylitol may become hypoglycemic. Dogs ingesting more than0.5 g/kg are at risk for severe liver toxicosis. It is important to remember that toxic doses vary per individual.
Plasma levels of xylitol in dogs peak in just 30 minutes and may cause symptoms of hypoglycemia in just 30-60 minutes; however, the hypoglycemic effects may be delayed for 24 to 48 hours due to individual metabolism, type of xylitol product ingested, and individual insulin production. It is thought that the xylitol causes a large increase in insulin release, which leads to the hypoglycemia.
Signs of hypoglycemia to remember are depressed mentation, weakness, seizures or tremoring, and ataxia. Many dogs also vomit after ingestion of xylitol.
Animals with hypoglycemia are treated with 2.5% to 5% dextrose constant rate infusion and frequent monitoring of blood glucose levels, usually for 24 hours (or longer if necessary). Animals with liver failure are treated with supportive care including IV fluids, liver protectants/antioxidants, and fresh frozen plasma if indicated for coagulopathy.
The bottom line is that xylitol toxicity should be considered a possible cause in a hypoglycemic animal, or an animal in acute liver failure. A pet may also have liver failure from xylitol toxicity and not have symptoms of hypoglycemia.
The prognosis for hypoglycemia alone that is treated appropriately is good, while the prognosis for liver toxicity and liver failure is poor.
For further reading and references:
1) Piscitelli, Christopher M., E.K. Dunager, M. Aumann. Xylitol Toxicity in Dogs. Compendium CE article. Vetlearn.com. February 2010. E1-E4.
2) Dunayer E.K. New findings on the effects of xylitol ingestion in dogs. VetMed 2006; 12:791-796.