Xylitol toxicity calculator for dogs

How much xylitol is toxic to dogs?

Very little. In people xylitol barely affects blood sugar, but in dogs it is absorbed quickly and triggers a large release of insulin, which can send blood sugar crashing. Larger doses can also destroy liver cells. The figures vets work from:

• 0.05 g/kg (50 mg/kg): Tox Info Suisse, the Swiss poison center, advises treatment from this dose.
• 0.1 g/kg (100 mg/kg): risk of low blood sugar (hypoglycemia), according to the Merck Veterinary Manual and the ASPCA Animal Poison Control Center.
• 0.5 g/kg (500 mg/kg): risk of severe liver injury or liver failure.

None of these is a safe line. The 0.5 g/kg figure is the lowest dose linked to liver failure in the ASPCA's early cases, and it isn't clear whether the liver damage depends on dose at all. Product labels also rarely give an exact amount, so the true dose can be higher than you think.

How much xylitol is in gum and other products?

Xylitol turns up in sugar-free gum, mints and candy, baked goods, some nut butters, cough syrup, chewable vitamins, supplements, toothpaste, mouthwash, over-the-counter medicines and sugar-free desserts. Labels may call it birch sugar or wood sugar.

Gum labels usually list total sugar alcohols rather than xylitol alone. An ASPCA toxicologist suggests this rule of thumb:

• If xylitol is the first sugar alcohol in the ingredients, count all the sugar alcohols per piece as xylitol. That overestimates the dose, which is the safe direction to be wrong in.
• If another sugar alcohol (sorbitol, maltitol, mannitol, isomalt) comes first, assume 0.3 g of xylitol per piece.
• Granulated xylitol weighs about 190 g per cup, so a teaspoon is about 4 g and a tablespoon about 11.9 g.

Some gums are mostly xylitol: Tox Info Suisse describes a 2 g piece holding about 1.8 g. If you can't check the label, choose “Not sure” in the calculator and it will show the range and judge the risk on the higher end.

Toxic amounts of xylitol by dog weight

Worked example: a 30 lb (13.6 kg) dog chews up 5 pieces of gum where xylitol is not listed first. That is about 1.5 g of xylitol, or 110 mg/kg: above the level that can drop blood sugar. If the same gum were mostly xylitol, the dose could be six times higher and into the liver range.

Symptoms of xylitol poisoning and how fast they start

Vomiting is usually the first sign. As blood sugar falls, dogs become weak, wobbly and lethargic, and they can collapse, seize or slip into a coma. The FDA notes that signs can begin within 10 to 60 minutes. With gum, which releases xylitol slowly, the drop can be delayed by up to 12 to 18 hours.

Liver injury follows a different clock. Liver enzymes can rise within 4 to 12 hours, but signs such as vomiting, lethargy, yellow gums and bleeding may not appear for 24 to 48 hours or longer. In one ASPCA case series, six of eight dogs with liver failure did not appear to have low blood sugar first, so a dog that seems fine is not in the clear.

What to do if your dog ate xylitol

1. Take the packet away and keep it: the brand and label matter to the vet.
2. Call your vet, an emergency clinic, or a poison hotline straight away: ASPCA Animal Poison Control at (888) 426-4435 or Pet Poison Helpline at (855) 764-7661. Both may charge a fee.
3. Don't make your dog vomit unless you're told to. Merck advises that it be tried only under veterinary supervision and only in a dog still acting normally, because signs can come on fast. If a vet does ask you to, the hydrogen peroxide calculator shows the amount.

Treatment centers on blood sugar. Vets typically check it every 1 to 2 hours for at least 12 hours, give IV dextrose if it drops, and recheck liver values every 24 hours for at least 72 hours. Activated charcoal is not expected to help much, since it binds xylitol poorly.

Are other sugar-free sweeteners dangerous to dogs?

The same ASPCA review found that other sugar alcohols, such as sorbitol and mannitol, have little or no effect on a dog's blood sugar or insulin, although large amounts can cause diarrhea. Sweeteners such as saccharin, aspartame and sucralose are generally regarded as unlikely to cause serious illness. Xylitol is the one to look for. For anything else your dog got into, try our is it toxic to dogs checker, and for chocolate-covered treats, the chocolate toxicity calculator.