That is my worse fear. My one dog is a pro at slipping out of her collar. She now has a martingale collar. I'm glad he came back to you without incident.
Misty- Samoyed Mix, Tannor- Golden Retriever CGC
Robyn- GSD CGC, TC, Midnite-GSD CGC,TC, Brennan-Golden Retriever CGC, Batman-Husky/Greyhound , Apollo-GSD