Why do animals touch my heart so?

Last night we go to leave for Austins football practice and walk out to a few visitors. On my porch there are 2 little puppies. I sit down to see them and a momma dog comes out from under a bush. These poor babies were in bad shape, but momma was in real bad shape. They are all skinny,over heated and flea infested. So, I give them all water and puppy food. The kids put them in the back yard and we headed to football. We came back and I gave them all a flea bath in the yard. The mom had more fleas than I had ever seen in my life. So, I separated the mom and puppies last night so mom could rest. The puppies are like 10 weeks and and still nursing, so mom was sucked of all her energy. This morning all 3 looked so much better. Energy and so lovable. They were crawling all over us and licking us.
I don't know what to do with these poor things. I don't live in the city, so they can't help me. I can't just let go back out, because that is not in my nature. I have 4 dogs of my own, I can't take on 3 more...They are so cute and sweet, it is breaking my heart. I don't know what it is with me, kids and animals just melt me.
Edit added 11pm
There was a knock at my door this afternoon. It was to former students. They ask if I had seen a white or brown puppy. I said" well yes and their momma too?" They said"oh yeah her too. I had half the mind to say no, but I didn't. I took them to my back yard to the threesome. I proceeded to tell them of the flea infestation, starvation, dehydration and filth of these poor animals,in a really nice way I promise. They proceeded to no care..The poor dogs ran and hid by me and did not want to go, but I handed them over. Well, the kids said thanks and went on about their day. We to went on about our day. I just went outside to check on my dogs and there was the momma dog again. No babies this time...UGH what now?