What the numbers mean
- Above 100 mg/kgBlood sugar crashes. Merck’s threshold. Can arrive within 30 minutes.
- Above 500 mg/kgSevere liver failure in some dogs, building over a day or two.
Xylitol tricks the dog’s pancreas into dumping insulin as if a huge load of sugar had arrived. It has not, so the blood sugar falls through the floor. Cats, ferrets and horses do not appear to do this. It is a dog problem.
Why nobody can tell you how much is in it
US labels do not have to print the xylitol content. The American College of Veterinary Pharmacists puts gum at roughly 300 to 2000 mg a piece, and Cornell notes the amount varies wildly and can differ between flavors of the same brand. That is a sevenfold spread, and it is why this calculator shows you a range rather than a number it cannot know.
There is one honest shortcut. If the label carries a Sugar Alcohol line in the nutrition panel and xylitol is the only sugar alcohol in the ingredients, that figure in grams is close enough to the xylitol per serving. Multiply by the servings they got and use the second tab above. If the ingredients also list sorbitol, maltitol or erythritol, the figure is a ceiling, not a dose.
Where it hides
- Sugar-free gum and mints. The usual culprit by a wide margin.
- Peanut butter. Most brands have none. A few "no sugar added" ones do, and peanut butter is what people use to hide tablets, so read the jar you own rather than trusting the brand.
- Toothpaste, mouthwash and dental gels — including some pet ones.
- Sugar-free baking, protein bars, chewable vitamins and children’s medicine.
- Anything sold as birch sugar. Same thing, friendlier name.
What to actually do
- Call now. This is one of the few poisonings where the clock is measured in minutes, not hours.
- Keep the packet. The poison lines hold manufacturer figures that are not on the label.
- If the dog is already wobbly, weak or having a fit, that is the low blood sugar. Go, and say so when you call so they have dextrose ready.
- A normal blood sugar tonight does not close the case. Liver damage shows up over the next 24 to 72 hours, so finish the recheck they book you for.