New products on the market such as nasal sprays, OTC sleep aids, multivitamins, prescription sedatives, antacids, stool softeners, smoking-cessation gums and other products may contain unexpectedly large amounts of xylitol. Dogs that ingest these products face a double risk—not only may poisoning result from the active ingredient but also from the xylitol. This can result in a variety of serious and unanticipated clinical signs that complicate treatment and prognosis.
Xylitol is a natural sugar alcohol normally found in small amounts in many fruits and vegetables. Because of its sweet taste and plaque-fighting properties, it is frequently used as a sugar substitute in chewing gum, breath mints and dental products like toothpaste and mouthwash. Nontoxic amounts are even found in some pet dental products. Due to its low glycemic index, it is also being sold in bulk to substitute for table sugar in baking and in-home use. As a result, PPH has seen several cases of dogs becoming severely intoxicated after ingesting homemade bread, muffins and cupcakes made with xylitol.
Determining the amount of xylitol in a product
Xylitol is typically considered part of a product's "proprietary ingredients," so the quantity will not be listed on the package label. While some companies are willing to release the amount of xylitol in their products, many are hesitant to do so and may even ask for veterinarians to sign a confidentiality statement prior to release. At PPH we've worked extremely hard to obtain as much information as possible about products with known xylitol content. Most companies have been willing to share information with us for use in emergency case management but request that it otherwise remain confidential. When you're in doubt of the xylitol quantity in a product, it's best to contact an animal poison control center for assistance.
Interpreting the placement of xylitol in an ingredient list
In some cases, it can be helpful to use the location of xylitol within an ingredient list to estimate its quantity in the product. For example, in the United States, all foods must list their ingredients in descending order of predominance by weight. This means that the ingredient that weighs the most is listed first, and the ingredient that weighs the least is listed last. In general, for most chewing gums, the amount of xylitol is often clinically insignificant if it's listed as the fourth or fifth ingredient. If it's listed as one of the first three ingredients, extreme caution should be taken.
For drugs and dietary supplements, the regulations regarding the order of ingredients is considerably different. In this case, xylitol is often considered an "inactive ingredient" or "other ingredient"—and such ingredients are not required to be listed in order of predominance. Often they are listed in alphabetical order, which may lead an uninformed pet owner or veterinary professional to incorrectly assume that there is a very low concentration of xylitol in the product.
New atypical sources of xylitol
Here are some products containing xylitol that you might not expect.
> Axia3 ProDigestive Antacid (flavored chewable tablets, propriety amount)
> Children's Allegra Oral Suspension
> Fleet Pedia-Lax Liquid Stool Softener
> Umcka Cold and Flu chewable tablets (homeopathic product).
Dietary supplements, vitamins:
> KAL Colostrum Chewable, Vanilla Cream (chewable tablets)
> KAL Dinosaurs Children's Vitamins and Minerals (chewable tablets)
> Kidz Digest Chewable Berry from Transformation Enzyme
> L'il Critters Fiber Gummy Bears
> Mega D3 Dots with 5,000 IU of Vitamin D3 per "dot" (dissolvable tablet)
> Stress Relax's Suntheanine L-Theanine chewable tablets
> Vitamin Code Kids by Garden of Life (chewable multivitamins)
> Super Sleep Soft Melts by Webber Natural (dissolvable tablets).
Press the next button below to read about more atypical sources of xylitol, toxic doses, and treatment recommendations.
> Xlear Sinus Care Spray
> Xylear Nasal Spray (for adults and children)
> Xyliseptic Nasal Spray.
> Abilify Discmelt Orally Disintegrating Tablets (aripiprazole), an atypical antipsychotic
> Clonazepam Orally Disintegrating Tablets, benzodiazepine
> Emtriva oral solution (emtricitabine), HIV-1 reverse transcriptase inhibitor
> Mobic Oral Suspension (meloxicam), nonsteroidal anti-inflammatory
> Neurontin (gabapentin) Oral Solution
> Riomet (metformin) Oral Solution, antidiabetic agent
> Varibar barium sulfate products, liquids and puddings for swallowing studies
> Zegerid Powder for Oral Suspension (omeprazole), proton pump inhibitor.
Foods with xylitol as the primary sweetener (excluding gums and mints):
> Clemmy's Rich and Creamy ice cream products
> Dr. John's products (hard and soft candies, chocolates, drink mixes and so on)
> Jell-O sugar-free pudding snacks
> Nature's Hollow jams, syrup, ketchup, honey and so on
> SparX Candy
> Zipfizz energy drink-mix powders.
Toxic doses and treatment recommendations
The toxicity of xylitol is dose-dependent. The dose necessary to cause hypoglycemia in dogs is approximately 0.1 grams/kg, while the amount needed to cause hepatic necrosis is approximately 0.5 grams/kg. Most chewing gums and breath mints typically contain 0.22 to 1.0 gram of xylitol per piece of gum or per mint. Therefore only one piece of gum may result in hypoglycemia in a 10-pound (4.5-kg) dog.
Hypoglycemia is typically evident within one to two hours of xylitol ingestion but in rare cases has been delayed as much as 12 hours. Prompt decontamination via the induction of emesis in asymptomatic patients with euglycemia is essential to prevent poisoning. Activated charcoal does not bind well to xylitol and is not typically necessary or recommended. Should hypoglycemia develop, supplementation with intravenous dextrose is needed until the dog can self-regulate its blood glucose concentrations (typically 12 to 48 hours).
For dogs exposed to hepatotoxic doses of xylitol, preemptive administration of dextrose (prior to the onset of hypoglycemia) may be helpful. Additionally, close monitoring of hepatic enzymes is warranted as evidence of necrosis may be seen one to two days following exposure. Should hepatic necrosis develop, IV fluids, dextrose, hepatoprotectants and monitoring of coagulation profiles are needed.
The prognosis following xylitol exposure is excellent when the ingestion is caught early, decontamination is performed, and blood glucose is monitored frequently. The prognosis becomes guarded if the dog has already begun to develop hepatic failure.
Dr. Ahna Brutlag is associate director of veterinary services for Pet Poison Helpline and SafetyCall International, PLLC.