Re-printed with permission
Authored by: Carlye Rose DVM, Dip. ABVP
What is Xylitol?
Xylitol is a white, crystalline sugar alcohol that is used as a sugar substitute sweetener in many products. In the United States, the use of xylitol has grown rapidly over the last few years. It is increasingly found in sugar-free gum, candy, and foods. It is also available in granulated form for baking. It is popular among diabetics and those on low-carbohydrate diets. It also is increasingly being included in toothpastes and other oral hygiene products due to its anti-cavity properties.
How is Xylitol Different in Humans than Dogs?
In humans, xylitol is absorbed slowly and has little to no effect on blood sugar or insulin levels. However, in dogs, xylitol is quickly absorbed into the bloodstream. It then acts as a strong promoter of insulin release, which causes profound hypoglycemia (low blood sugar). In dogs, xylitol can also cause liver failure, bleeding, and death.
How much Xylitol is Toxic to my Pet?
It takes very little xylitol to cause signs of toxicity in dogs. The ASPCA Animal Poison Control Center (APCC) has reported that dogs ingesting greater than 0.22 grams per pound of body weight of xylitol should be considered at risk for hypoglycemia. At doses exceeding 1.1 grams per pound of body weight, there is risk of liver failure and other more serious effects.
It is often difficult to determine exactly how many grams of xylitol were ingested. Although the xylitol content is more commonly listed on food products, this is not the case with many chewing gums. In general, we estimate that one or two pieces of gum could cause hypoglycemia in a 20 lb dog.
Dr. Terifaj notes: In comparison, approximately 1 ounce (28 grams) per pound of body weight of milk chocolate or 1/2 ounce per pound of body weight of dark chocolate is toxic to dogs. On a consumption basis, xylitol is over 100 times more toxic than chocolate! Chocolate contains theobromine that is toxic to dogs in sufficient quantities. This is a xanthine compound in the same family of caffeine and theophylline. On average, it takes a fairly large amount of theobromine to cause a toxic reaction. Xanthines affect the nervous system and cardiovascular system. Symptoms may include: hyper-excitability, hyper-irritability, increased heart rate, restlessness, and muscle tremors. Most often, dogs don’t consume enough theobromine to cause a toxic reaction. Lesser amounts can cause gastrointestinal signs: vomiting and/or diarrhea.
What are the Symptoms? What Tests can be done to Diagnose Xylitol Toxicity?
Diagnosis is made on history of ingestion, symptoms, and blood work. Because of the rapid progression of the toxic effect, testing for xylitol in the blood is not realistic.
Dogs that develop acute liver failure may not show signs of hypoglycemia immediately after ingestion of xylitol.
What other Toxins Should be Ruled Out?
Other causes of low blood sugar should be ruled out (overdose of insulin, young or toy breed – related hypoglycemia, etc). In addition, many other toxins can cause liver disease (sago palms, hepatotoxic mushrooms, Tylenol ®, aflatoxins, other drugs). Dr. Terifaj notes: Aflatoxins are molds that have been found in pet foods that contain contaminated grains.
Is Xylitol Poisoning Treatable?
What is the Prognosis?
The prognosis is good for uncomplicated hypoglycemia when treatment can be instituted promptly. Liver failure and bleeding disorders generally carry a poor prognosis. Dogs that develop stupor or coma have a grave prognosis.
Is it an Epidemic?
“In the last few years, xylitol has grown from being a rare (or non-existent) problem to being a very common one. The dictionary defines epidemic as ‘affecting or tending to affect a disproportionately large number of individuals within a population, community, or region at the same time’…so… technically you can call xylitol an epidemic.” – Eric Dunayer, MS, VMD, DABT, DABVT; ASPCA APCC; VIN, 8/16/2008
The number of products containing xylitol has been steadily rising over the last few years, with a resultant surge in xylitol cases reported to the ASPCA Animal Poison Control Center.
Xylitol poisoning is preventable. Xylitol-containing foods or gums should not be consumed in pet-owning households.
Dr. Terifaj notes: While xylitol products are safe for people, they are poison for our canine pets. What’s worse is that products that contain xylitol don’t always list it as an ingredient. Sometimes it is just called “sugar alcohol,” although that could also mean sorbitol or mannitol. The safest thing to do is to keep all sugar-free foods, and all foods that say they contain xylitol or “sugar alcohol”, away from dogs. Especially chewing gum!
It is of utmost importance to read the labels on any pet or human products you buy — this is just one more example of why. FYI: Since fluoride containing toothpastes have come under scrutiny — as to their human safety — many health conscious folks have switched to toothpastes that contain xylitol, including myself. Since dogs are more apt to search out chewing gums, candies, breath mints and foods, than your toothpaste, this is less of a concern, unless your dog is brushing with your toothpaste!