Xylitol
Toxic to dogs
Xylitol — sometimes labelled 'birch sugar' or 'wood sugar' — can cause a sudden, dangerous drop in blood sugar in dogs and, less often, liver damage.
- FDA — Paws Off Xylitol; It's Dangerous for Dogs
- Merck Veterinary Manual — Xylitol Toxicosis in Dogs
- ASPCA Animal Poison Control Center — People Foods to Avoid Feeding Your Pets
- FDA Center for Veterinary Medicine — Paws Off! Xylitol is Toxic to Dogs
That the E-number names this substance: Commission Regulation (EU) No 231/2012 — specifications for food additives
Sources checked 2026-10-12. If you think a pet has eaten something harmful, contact your vet or an animal poison control line straight away. This is not veterinary advice.
The short version
A natural sugar alcohol with the sweetness of sucrose but about 40% fewer calories.
For people, it's a sugar-free sweetener considered safe at the amounts used in food — that's what the green means. It is not safe for dogs: see "In pet food" above.
Safety profile
No ADI specified. Considered safe for humans. Doses above 30–50 g/day can cause diarrhea due to osmotic effect. Dogs are different: in dogs xylitol can cause a sudden, dangerous drop in blood sugar and, less often, liver damage; how severe it is depends on how much is eaten (FDA; Merck Veterinary Manual).
Sources
- WHO JECFA database — Xylitol (INS 967), ADI 'not specified' (evaluation 1983) — Joint FAO/WHO Expert Committee on Food Additives (JECFA), WHO, 1983. No ADI specified
- FDA Consumer Update — Paws Off Xylitol; It's Dangerous for Dogs — U.S. Food and Drug Administration, 2025. In dogs xylitol can cause a sudden, dangerous drop in blood sugar
- 21 CFR 172.395 — Xylitol (CFR, 2025 edition) — U.S. Government Publishing Office / FDA, 2025. Permitted as a food additive in the US
- Regulation (EU) No 1169/2011 on food information to consumers — Annex III point 2.4 (polyols) — European Union, Official Journal, 2011. Mandatory laxative warning above a set level (EU: foods with more than 10% added polyols)
Checked against these sources on .
Educational information only. Not medical, dietary or veterinary advice. Spotted an error? Tell us.