I don't know how it is possible, but we don't really have a massive stray dog problem in Chiang Mai. There are a few in my neighborhood but they are looked after by a lot of people including me. I put water out for them every day and if they come by and want to sit in the shade in my yard I let them. It's funny because in the cold season someone always puts a shirt on them as well. I don't think anyone lets them inside though.