I rescue stray dogs and I need to know if there is any help for me?

I rescue stray dogs and i heal them, clean them, feed them, and find them homes which can be hard because the animals dont always leave right away. I live in houston tx and I would like to know if anyone knows if I need a permit for this or if there is any help I can receive from the city for doing this? I dont like taking them to the shelters because a lot of them get humanely put to sleep as soon as they go in. Any advice?