Xylitol (birch sugar) in Pets

Estimate a dog's xylitol dose from sugar-free gum or peanut butter and compare it with the 100 mg/kg low-blood-sugar and 500 mg/kg liver thresholds in the Merck Veterinary Manual.

What It Is

Xylitol is a sugar alcohol used as a low-calorie sweetener. In people it barely affects blood sugar, but in dogs it triggers a rapid, large release of insulin, which can drop blood sugar to dangerous levels within minutes. Higher doses can also damage the liver.

Where Pets Come Across It

Sugar-free chewing gum and mints are the classic source, followed by sugar-free sweets, some peanut and nut butters, baked goods made with birch sugar, chewable vitamins, toothpaste and mouthwash. Some liquid medicines made for people also contain xylitol. Labels may say xylitol, birch sugar or E967.

Which Animals Are Affected

Dogs are the species of concern. Cats appear much less affected on current evidence, and data in other pets are limited, so call a poison line for any species.

Published Toxic Dose

According to the Merck Veterinary Manual, doses above roughly 100 mg/kg have been associated with low blood sugar in dogs, and some dogs eating more than 500 mg/kg develop severe liver injury or failure. The xylitol content of gum varies widely between brands, from well under 0.5 g to more than 1 g per piece, and many packets do not state it, so a poison line may need to look up the exact product.

Xylitol (birch sugar) Dose Exposure Calculator

Enter your pet's weight and estimated quantity missing to compare against veterinary literature thresholds.

Affected Species Dog (Canine) Cat (Feline)

Pet Body Weight

kg lb

Number of Pieces of Gum / Mints

Xylitol Content per Piece (mg) Check the label or the maker's website. Gum ranges from well under 0.5 g to more than 1 g per piece.

Calculating...

Signs and How Soon They Appear

Weakness, wobbliness, vomiting, collapse and seizures from low blood sugar can begin within 10 to 60 minutes. With some gums the onset is delayed by up to about 12 hours. Signs of liver damage, such as vomiting, yellow gums and bleeding, may appear one to three days later, sometimes without earlier low-sugar signs.

What to Do Right Now

Call immediately; this is one of the fastest-acting pet poisons. Keep the packaging so the xylitol content can be identified. Do not wait for signs, and do not make your dog vomit at home. If your dog is already weak or collapsing, go straight to the nearest emergency vet.

Frequently Asked Questions

Sources and References

• Merck Veterinary Manual: Xylitol Toxicosis in Dogs
• Pet Poison Helpline: Xylitol

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