I guess my point was that pets here are let to roam as they please and breed as they please, contributing to the massive stray population
You're right, it's not strange. I actually meant that the dogs live on the streets of Bangkok city and roam like an outdoor cat would, even if they have an owner. It's hard to tell the difference between them and strays as they're not cleaner or healthier. You might assume they are strays, but a hawker or motorbike taxi will tell you the dog is "claimed" so you aren't able to rescue them without technically stealing.