Hi guys! I've been having issues recently with my almost 7 month old GSD. Let me give you some background to better explain the situation. I have two miniature horses who are about twice his size that I take out to the pasture once every day. Magnum is an outside dog who has a very high prey drive, and because of that I keep him on a tie out when I can't keep him near me (like when I need to bring the horses out to the pasture). He's perfectly fine every other time when he's on the tie out, but recently he's been freaking out (barking and pulling excessively) whenever I start to halter the horses to bring them out. Tonight he ended up breaking his 1-1/2" leather collar! Is he jealous that I'm paying attention to the horses and bringing them out, or is he afraid that his friends are leaving him? I always come back to him afterwards to play and he's totally fine then. He will be starting obedience classes in a few weeks, but I'd like any advice you could give me about this.