Don and I live in Texas and have two Berners. We also have three quarer horses (bred for cutting). We have 25 acrses but the dogs are not allowed to wonder all over; kept in a fenced-in yard. However, a lot of times we let them out to go with us to feed the horses and they know and love each other; never any aggression shown.
About four years ago, had a new puppy and I was just getting where I could walk a little; cast on my leg and foot had just been taken off and I took a young puppy out in the back and Oh, gosh, she was headed for the horses---fence between them but she could get under easily. I was hobbling out there as fast as I could but could see I wasn't going to make it before she was right with the horses and she would be new to them; what would they do. All of a sudden, Don's German Shepherd (bred for tracking, herding) came out from nowhere and worked his way under the horse fence and herded them back and then nosed the baby up to me and then just looked up at me as if to say "you need to take better care of your baby" and off Bridget went to play. We also have a Border Collie who also herds the horses but really hasn't been trained---she leads them in; doesn't get behind them. As my daughter says, Ben acts like a guy who parks cars, "keeps coming at you in your car and then runs ahead like, "here, here, Park Here!. Dogs and Horses---in my opinion, they get along great. Margie Clark