My inlaws took care of a fawn for several months last year, and it did the same thing with their horses. They had a couple of large horse pens, and the deer would get in there and run around with them. That deer was so confused, it reminded of the children's book "Are you my mother" because this deer would walk from the horses, to the barn cats, to the dogs. Not only that, you could walk out on the back deck, call out it's name, (yes, they named it Bob) andhe would come running out of the woods. No kidding. Funny stuff.