Glad to see this problem posted here, as I also had a similar problem just last week. My mare had apparently bonded with another mare across a fence. The mare had been removed from the pasture for about five days for breeding. Due to logistics at our barn, I had to walk my mare by the breeding area a couple of nights. I walked her as far away as possible, because I realized that she was very excited whenever she saw the breeding mares. I was curious about it, but didn't give it any more thought.
When the brood mare was returned to her pasture is when the fun began. My mare would not leave the gate separating the two pastures, and was trying to get through it. She was also frantically running the fence. I actually pulled her up to the barn to groom and feed her the first evening, thinking I would ride her also. About half way up, I realized that we had a real issue, as she was screaming, pushing me around, whipping around to look in the direction of the pasture. I have never seen this side of her before! Needless to say, I wasn't about to ride her that night, as the inside arena is adjacent to some stalls housing stud colts with whom she was also having a conversation... Friday she was finally back in her pasture away from the brood mares, and we had a good ride. Whew... I can't wait until things are back to normal when breeding season is over!
Oh, and my mare did have some minor cuts and abrasions on her back legs, I'm sure resulting from working that fence and gate between the two pastures!