Leo,

You need to be 500ft away or further from a dwelling (inhabited or not, including barns), unless you have written permission to be closer.

The regs state that you cannot shoot in the direction of a dwelling, domestic animals or livestock. As long as you don't shoot towards the horse, there's nothing the landowner can do to you or your hunting partners.

I'm just curious though...with 225 acres, the only/best spots you found were within the immediate vicinity of your neighbors horse fields? Not doubting it, just curious if some more scouting might provide a more "amicable resolution" to your problem...

S&R