In highschool I came home to a familiar-looking black brown and white dog.
My sister’s dog usually barked nonstop if she saw another dog outside, but this time she just kept staring and occasionally whining like she needed to pee.
After calling the number on the collar, it turns out they’re litter mates and they lived about 30 miles away, the dog had disappeared from the yard two days beforehand and wandered across corn fields, an entire town, and a bunch of cow pastures along with plenty of heavily-wooded areas, and one stream about 50ft across.
No idea if the dog just decided to go looking one day, or if he was just casually wandering and managed to catch a scent he recognized. I’m betting it was a random chance encounter.
Unfortunately for the other owners, after he found us, he kept intentionally escaping to show up at our door within 12 hours.