Ahhh don't you hate that. We also live in a remote area, and people think nothing of dropping off their discards. My neighbor on Monday came to my door to see if I had an extra lease she could borrow. She had spotted a puppy out in the desert on her way home and she was going to try and rescue it before the buzzards got to it. She brought it back by on her way home, and he was so skinny, and dehydrated. Poor guy was shaking so badly, but he looked relieved to actually be around people. I need to check with her this weekend to see how it is doing. She has already recused 3 other drop off dogs, so I am sure this will add to her group. It is lucky our neighbors are all animal nuts. In our area, there are coyotes, javalina (wild pigs), rattle snakes, buzzards and eagles. All of these make a puppy easy prey and dinner. We often see signs of 'missing Chihuahua and Yorkies' along the highway from people who have just moved into the area. Cats are another that are often prey.
People just don't think about how small these animals are, and what kind of wild animals are in our area. Even though we have a block fence around our property, one winter we actually did have a mountain lion in our back yard. We had to call game and fish to come and ensure it wasn't in there the next morning before we let our kids out to play. We have only had on instance of that, but we are always on guard before we open our door in the morning. While we have 3 good size dogs our Pekeneese has to be guarded (although he is so fisty - I think he would give a good fight).