By Everyday Health Guest Contributor
Published Nov 13, 2015
By Jeff Werber, DVM, Special to Everyday Health
Did you know that the popular sugar substitute xylitol poses a serious threat to your pet dog?
You’ll find xylitol added as a sweetener in many products, such as sugarless gum, mints, low-calorie baked goods, oral care products, and now even in reduced-calorie peanut butter. Xylitol is actually about as sweet as table sugar, but it contains 40 percent fewer calories. While considered safe for human consumption, xylitol is very toxic to dogs. In high enough doses, it can be lethal. Here’s why.
Xylitol Acts Differently in Dogs
Typically when we eat sugar or carbohydrates, our bodies respond by secreting insulin from the pancreas, which stimulates and controls the absorption of these sugars into our cells for energy. In people, oral xylitol absorption is very slow and not complete; what’s more, xylitol doesn’t require insulin to enter our cells. As a result, overall blood sugar levels remain fairly stable when people eat something containing xylitol.
For your pet dog, however, it’s a different story: When a dog eats something with xylitol, the absorption is very rapid and totally complete. It seems that in a dog, xylitol does cause a release of insulin into the bloodstream, actually a much greater amount than would be released from an equivalent amount of glucose. This insulin then causes vast amounts of blood sugar to be absorbed into the dog’s cells that don’t need the sugar. By doing so, xylitol causes potentially severe low blood sugar, or hypoglycemia. Even if the dog is given oral glucose, blood sugar levels remain low.
As little as one-tenth of a gram (g) of xylitol per kilogram (kg) of the dog’s weight can cause hypoglycemia.
Signs of Xylitol Poisoning in Dogs
Early signs of xylitol ingestion in a dog might be vomiting, which can be a good thing because it helps to get rid of the offending food. Hypoglycemia may occur within 30 minutes to an hour. In some cases, if the absorption of xylitol is slowed down, as when a dog ingests chewing gum meant for people, the onset of hypoglycemia in the dog may be delayed up to 12 hours.
Depending on the degree of hypoglycemia, a dog’s symptoms may progress to weakness, ataxia (loss of control of the body’s movements), seizures, and collapse.
As if this isn’t bad enough, higher doses of xylitol ingestion, usually over 0.5 g/kg, have other toxic effects. At this dose, blood sugar levels are not affected, but the liver is. Severe toxic effects on the liver include elevated liver enzymes somewhere between 12 to 24 hours after ingestion, and several dogs developed acute liver failure after xylitol ingestion. They had lethargy and vomiting up to three days after xylitol exposure, and many developed blood coagulation deficiencies due to the liver failure. In addition to elevated liver enzymes, many of these dogs had elevated phosphate levels in their blood.
Many diseases and conditions can cause hypoglycemia, as well as acute liver disease. Because of this, it is imperative to have your dog examined by your veterinarian if there is any possibility that he or she could have ingested xylitol. This is critical if your dog seems to become weak or lethargic, suddenly begins to wobble, seize, or collapse, begins to vomit, is not interested in food, or seems to develop bruises or pin-point red dots or blotches on the skin, inside the ears, or on the gums (known to veterinarians as petechial hemorrhages).
In most cases, if caught early — and depending on the dose consumed — dogs that ingest xylitol can be successfully treated. If you have any questions, be sure to consult your veterinarian.
Dr. Jeff Werber is a renowned veterinarian and pet-parenting specialist dedicated to the care and protection of animals. He cares for the pets of Britney Spears, Julia Roberts, Ben Affleck, Eddie Murphy, Paula Abdul, Rod Stewart, Mark Wahlberg, Patrick Dempsey, Mandy Moore, Jennifer Love Hewitt, along with those of everyday pet owners, at his Los Angeles-based private clinic, Century Veterinary Group. He has appeared on The Early Show on CBS, the Fox News Channel, and the Rachael Ray Show. As an Emmy Award-winning veterinarian, he hosted Petcetera on Animal Planet , and currently hosts Pet Care TV.