Radicchio — Food safety facts
Safe to share · Dogs · full breakdown on the linked food page
Safe in small amounts.
The full verdict, portion guidance and serving notes are collected on the Radicchio food facts page.
Short answer
No, it's not safe once it's been left out. While fresh radicchio is fine in small amounts, salad left at room temperature can grow bacteria or mould that can cause significant stomach upset, vomiting, or diarrhoea in dogs. Discard any wilted or slimy leaves, and never offer your dog food that has been sitting out for more than a couple of hours. If your dog has eaten spoiled radicchio and starts acting unwell, offer plenty of water and call your own vet for advice.