Cinnamon — Food safety facts
Feed with care · Dogs · full breakdown on the linked food page
A pinch of powder is usually fine. Large amounts irritate the mouth and stomach and can lower blood sugar.
Short answer
Yes, a pinch of ground cinnamon is generally safe for dogs. Cinnamon in small amounts usually doesn't cause problems. If your dog eats a larger quantity, it can irritate the mouth and stomach and may lower blood sugar. Watch for drooling, vomiting, or signs of weakness and call your vet if any appear.