For about 4 years, we have had a gelding (Major) and a mare (Millie), both Walkers. The gelding had been foundered before we got him and the mare had been neglected.
Recently, we decided to get another horse because Major is getting older and just not able to handle multiple days of trail riding. We got another gelding (Big Country) and immediately the mare became mean to him. She starting biting him, peeing on him and just awful. I decided to take her to a local trainer that would work with her for a few days before we left on a long weekend ride. He agreed that she was aggressive and mean to his other horse and even moved her to another field. We picked her up Friday and along with Big Country and headed to camp for three days. She acted fine with Big Country and the other horses. But when we got home, she went crazy again and now is being mean to Major.
I have no idea what to do.
Thanks for any suggestions.