Short answer
Plain raw pumpkin seeds rarely cause issues in dogs. If your dog reacts at all, mild stomach upset like soft stools might appear within 6-12 hours. Serious poisoning isn't expected, but watch for vomiting or loss of appetite. Offer water and skip the next meal if his belly seems off. Call your usual vet if symptoms last more than a day.
Pumpkin seeds — Food safety facts
Safe to share · Dogs · full breakdown on the linked food page
Plain unsalted pumpkin seeds are safe in small amounts.
The full verdict, portion guidance and serving notes are collected on the Pumpkin seeds food facts page.