Was this the article that talks about the xenophobic behavior in lost dogs?
Recovery Tips: Think Lost, Not Stray | Missing Pet Partnership
I think the legal limit before a found dog is considered "yours", and there fore you are legally allowed to have them spayed/neutered varies with each area. In Forsyth County, it's only 72 hours! The shelters in your area will tell you.
Poor little guy. No matter what the circumstances that led up to him being on the street yesterday, at least he is in safe hands right now.