Xylitol: A Hidden Danger for Your Dog

by Dr. S. Dawn Dinger, DVM

Have you ever heard of xylitol?  Sounds exotic, but chances are you have some in your home right now and it is truly a danger hiding in plain sight for your dog.

Xylitol (pronounced zi-li-tol) is a natural sugar substitute and can be found in many sugar free food items such as gum, but as it also has natural anti-cavity effects, it can also found in some toothpastes and mouthwashes.  In fact, more and more food items and personal care products, including some peanut butters, ice creams, candies, energy drinks and medications, contain xylitol.  Click here for an extensive list of products.  

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Despite all of it's perks for use in people, xylitol is highly toxic to dogs.  Dogs need to ingest much  smaller amounts of xylitol than chocolate to be become poisoned and many pet owners are unaware of the dangers, so cases of poisonings are becoming more and more frequent.  Unlike in people, xylitol stimulates the release of insulin in dogs which can lead to life threatening hypoglycemia (low blood sugar).  Signs of hypoglycemia in dogs can include weakness, seizures and coma and can develop in as little as 30 minutes after ingestion, but can be delayed out to about 18 hours if the xylitol is contained in a substance which will slow it's absorption (like gum).  However, the problems don't end there.  Several days after ingestion of xylitol, some dogs will develop acute liver failure.  Many of the dogs that develop liver failure did not develop low blood sugar after the initial ingestion.  At this time, it is not known why that occurs.

So how much is too much?  Dogs need to ingest about 0.1 gr/kg (gram/kilogram) of xylitol to develop hypoglycemia and about 0.5 gr/kg to develop liver failure.  So a 20 pound dog would need to ingest 0.9 gr to become hypoglycemic and about 4.5 gr to be at risk for liver failure.  A sugar packet typically contains about 1 gr of xylitol and a stick of gum typically contains 0.3 – 2 gr of xylitol.  So this means that our 20 pound example dog would only need to ingest one or two sticks of gum to be in big trouble.  As any dog owner knows, most of our goofy, glutinous canine friends can swallow that in a gulp.

What happens then if you come out to the kitchen and find that your dog has gotten into your purse and ingested a pack of sugar free gum?  First, call us immediately!  If this is at a time we are not in the office, call a veterinary emergency room (See PVSEC's information at the bottom of our website).  Your dog will likely need to be seen right away.  Make certain to take the package of food, medication etc with you and try to have an idea of how much your dog ate.  Your veterinarian will need to try and calculate the dose of xylitol that you dog ingested.  Sometimes that is easier said than done – xylitol may be listed on the ingredient list, but the actual concentration is often considered proprietary information and can be difficult to obtain.  Your vet may need to go on the “most likely” maximum amount ingested based on averages that that type of product typically contains.

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Depending on when ingestion occurred and how much was ingested, your vet may induce vomiting in your dog to help get rid of as much product as possible.  They will also likely need to check labwork, including blood glucose level and liver values.  At at minimum your dog may need to be admitted and monitored for some time to make certain no problems develop.  If your dog is already hypoglycemic, then they will need to be hospitalized on intravenous (IV) fluids and dextrose (a sugar).  Low blood sugar can persist 12 – 48 hours; once your dog is able to maintain his blood glucose within normal range on his own he will be able to go home, but will need monitoring of his blood glucose and liver values over another few days.  Luckily the prognosis is good if no signs develop or if the hypoglycemia is treated rapidly.  

Unfortunately, the same can not be said for those dogs that develop liver failure.  Signs of liver failure can include vomiting, diarrhea, dark/tarry stools, jaundice (yellow gums or skin), bleeding, or bruising and typically develop 2-3 days after ingestion.  Liver failure is treated aggressively with things like fluids, plasma transfusions, antibiotics and liver protectants, but there is no specific antidote for xylitol toxicity.  Sadly, once liver failure develops, the prognosis is poor.  

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Obviously, the best thing you can do is to prevent exposure in the first place.  Never leave purses, bags etc out where curious canines can get into them. Never allow pets to beg or receive food from the table.  Be especially careful if anyone at home is a diabetic or if you do any sugar free baking.  Make certain to keep all medications out of reach and be careful when walking your dog too – those discarded wads of gum on the sidewalk can be snatched up by your pup very quickly.  Don't forget to check the ingredient lists on packages also, especially on anything that you might use to make a treat for your dog.  Some “key words” that should put up red flags include: sugar free; reduced sugar; all natural; no artificial sweeteners; birch sugar; safe for diabetics; low carb; low cal; and anti-cavity.  

And lastly, a word about cats.  Does xylitol affect them the way it does dogs?  In short, we don't know.  According to National Animal Poison Control, to date there have been no reported cases of toxicity developing in cats.  Is that because they are more resistant to xylitol's effects, or just because cats are less greedy than dogs and so less likely to ingest things like gum and candies?  Again, we don't know, so the safest course of action is to keep your cat away from these products as well.  ​​​

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