We have taken, for
the time, a foster small dog that had been in a no-kill shelter for
about a year, and while he had exercise walks, he was most of the time in a confinement area, one we didn't see. They bring dogs out based on their list, potential adopters do not tour the dog holding facility.
So, the little guy we brought home, about 15 pounds and perhaps 5 years old, has to be trained to deal with a home environment including toilet training.