I hope I can get some sound advice from those of you who rescue/foster. I found a cat on my way home yesterday she is just a skeleton with fur stretched over her right now. She is very friendly, and considering her condition she doesn't appear to be lethargic. I am pretty sure she is dehydrated (nap of the neck test). She has a lot of fleas, and this morning I foung two fairly large freely moving masses in her abdomen.
I kept her in a big dog carrier with fresh food/water & makeshift litter box on the side of my house (yes outside ) last night. I am taking her to the vet in the morning. I don't want to let her roam free I am afraid she'll run away. With my three cats being indoors I don't want to expose them to anything she may have.
She is getting lots of love from all of the neighborhood kids and me too of course! I feel guilty for keeping her in the carrier but I just don't know what else to do.

I hope I am doing the right thing