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A Sweet Disaster – Xylitol in Dogs



A Sweet Disaster – Xylitol in Dogs

Rod Bagley





Xylitol, a common artificial sweetener, is found in sugar-free gums, oral care products, and baked goods, as well as in low concentrations naturally in fruits, berries, vegetables, and mushrooms. While harmless to humans, it presents a unique toxicity for dogs. Little data is available to supports its toxic effects in cats.


In humans peak plasma concentrations occur in 3-4 hours, whereas in dogs peak levels are achieved in as little as 30 minutes, though in some cases can be delayed as long as 12-48 hours.


Even at low doses (0.1mg/kg), xylitol stimulates 2.5-7-fold increases in endogenous insulin release, resulting in rapid onset of severe hypoglycemia, characterized by lethargy, depression, tremors, or seizures.


Xylitol is metabolized by the pentose phosphate pathway in the liver, the by-products of which result in depletion of hepatocellular ADP/ATP stores.


As a result, liver cells lose their normal metabolic function, resulting in hepatocellular necrosis and subsequent liver failure. Signs of liver failure can develop even in the absence of hypoglycemic crisis in some patients, with the original ingested dose not associated with survival probability.


While onset of liver toxicity is generally within 9-72 hours, signs have been reported to be as delayed as much as several weeks.


For dogs ingesting 0.1-0.5mg/kg, treatment generally consists of hospitalization, fluid therapy, monitoring, and management of the hypoglycemia.


While most dogs improve with dextrose supplementation alone, dextrose administration can stimulate further insulin release, thus in refractory cases glucagon therapy may be indicated.

For dogs ingesting >0.5mg/kg, treatment goals are similar, with more diligent monitoring and management to minimize risk of developing liver failure.


The duration of treatment is dependent on normalization of blood glucose and electrolyte balance without the need for supplementation.


The prognosis overall for patients with uncomplicated hypoglycemia from xylitol toxicity is good, whereas the prognosis for dogs developing hepatic necrosis and liver failure is guarded to poor.


An ounce of protection is invaluable, as an ounce of ingestion can be deadly!