Rather than bug (overisght? Or whatever is the word.) it is just reason of hitboxes. Horse, boat, etc. hitboxes are bigger than your own and You cannot fed animals .
If You position yourself decently next to animals, which is 99% times hard or impossible when animals move, it is possible to do so.
Aware, but perhaps not really a bug either. Have looked at this before and decided to not fix it.
"The psychological trials of dwellers in the last times will be equal to the physical trials of the martyrs. In order to face these trials we must be living in a different world."