What is xylitol?

Xylitol is a sugar substitute.  It is found most commonly in sugarless gums, sugarless candy and other food products.  Xylitol offers the sweetness without adding on calories.  It also helps to reduce periodontal disease, and it may help with other diseases as well.  This is all well and good for humans, but in dogs xylitol is a poison.  Xylitol can produce two deadly effects on dogs-hypoglycemia and hepatic necrosis.

Hypoglycemia(low blood sugar)

Xylitol can cause weakness, disorientation, tremors, seizures and death.  Vomiting and diarrhea can also occur.  In the dog, insulin is released from the pancreas when then is excess glucose in circulation.  The trouble with Xylitol is that the pancreas sees this as a real sugar.  The pancreas releases insulin to help remove the "real sugar" from circulation, which in turn causes the blood glucose level to plummet.  When the blood glucose plumments clinical signs previously described occur.  It only takes 0.1grams per kilogram of body weight(0.045 grams per pound) of xylitol to produce hypoglycemia in dogs.  One stick of gum contains 0.3-0.4 grams of Xylitol.  A 10 pound dog would only need to eat 1 and 1/2 sticks of gum to produce hypoglycemia.  Clinical signs of low blood sugar usually occur within 30 minutes of ingestion and hypoglycemia can last between 12-24 hours. 

Hepatic Necrosis

Xylitol can produce destruction of the liver tissue(hepatic necrosis).  How xylitol does this has yet to be determined.  Clinical signs take longer to be seen, usually within 8-10 hours post ingestion.  Some dogs that have hepatic necrosis do not show signs of hypoglycemia first.  Acute liver failure can result in death.  Internal bleeding and the inability to clot blood is commonly involved.  Doses for seeing hepatic necrosis is usually higher.  The dose to cause liver failure is 1 gram per kilogram of body weight(about 10 times the dose for hypoglycemia).  So to induce liver failure in a 10 pound dog, the dog would need to consume a pack of gum.

Treatment

If the ingestion is witnessed then seeking emergency veterinary care as soon as possible is ideal(preferably within 30 minutes).  The veterinarian will then induce vomiting.  After this time period the dog is usually admitted into the hospital and placed no IV fluids containing dextrose for the next 24 hours.  Liver tests, electrolytes(sodium, potassium and chloride) and blood clotting tests are performed over a  3 day time period to monitor for liver failure.

Prevention

Keeping all sugarless products containing Xylitol out of the dog's reach is the best.  Also monitoring your dog when the dog is out for a walk and ensuring the dog is not eating things off the ground.

Cats

To date there have been no known cases of toxicity reported to the Animal Poison Control Center.  Thus, at the present time toxicity from xylitol is unknown.