An unregulated at-home for-profit daycare is one of the reasons I now have a pants-shitting dog-phobia. Lady who ran it also bred dobermans and let us play with the puppies to entertain us while she was busy, and the mother dog got so mad she jumped through and broke a window's glass to bite at us.

The dogs were aggressive (her fault, not theirs), and she kept the adult dogs in a fenced off area in the backyard. If you swung high enough on the swing set, you'd be right over their enclosure, and they'd jump up to bite your feet. We played chicken like that a lot til a few shoes were lost.