Here in Argetina things are very different, and with thta said: About 10 years ago a took a foster dog from a rescue, she was agresive and had a few medical issues. She and my dog got along pretty well so even though sometimes she would attack me I kept fostering her. Fastfoward a year, I've been paying everything out of my own pocket, food, vet, toys, everything; my dog got really sick and I asked the rescue to come and get her, because I coudn't hande the stress and she would bite the vet that was coming to my home 3 o 4 times a day. They got angry at me, they insulted me saying I adopted her (that was not the case at all) but after I got really, really, really angry they took her back. My dog ended up dying from a rare leukemia. I didn't foster again, I adopted 2 mora dogs and a cat, but without the things you are listing, sadly I won't be a foster.