Food safety
Can dogs eat xylitol / birch sugar?
No — don't give this
A sweetener in sugar-free gum, mints, some peanut butters, baked goods and some medicines. Very small amounts can cause a dangerous drop in blood sugar.
If your dog has already eaten it
This is an emergency. Call a vet immediately.
Being honest about this
Dogs differ, and amount matters — a crumb of something rich is not the same as half a packet. Treats of any kind should stay under a tenth of what your dog eats in a day. If you're unsure, your vet would far rather take the call.
Based on guidance from: Toxic food guidance for dogs — Animal Poison Line / VPIS
Sources & methodology