I always make an effort to find a lost dog's owners, or even a cat if it looks unhealthy (most cats around here are outdoor anyway, but if one looks real scraggaly or in bad shape, I'll try to find who it belongs to in case it's been lost for a few days).
I always try to imagine if it was my dog who was lost, and how I'd feel.I'd be crushed.
Also, there's some people out there who run animals over on purpose.
Not on my watch, buddy.