My old man Cricket has been with the same pasture group for quite a while now - 2 geldings and a mare. He is the lowest horse in the pecking order in this group, but things have been peaceful for many months. Cricket gets to eat (not always the prime hay pile, but it's all the same hay anyway,) drink, and move about with the group. He may have to linger on the fringe of the shelter instead of being snuggled all the way inside it, but I wasn't concerned about him. He got to come into the barn on the worst of the winter nights, and his weight has been steady all winter. In the last month or so, he has started being pushed farther out of the shelter and being forced to go the long way around to the farthest hay pile to eat. The tail flap on his heavyweight blanket was "mysteriously" missing, and there are many tooth marks on the rump of said blanket. In the last two weeks, he's become a picky eater, leaving a goodly portion of his twice-daily beet pulp-alfalfa pellet-senior mash instead of just leaving the big chunks of beet pulp that he doesn't like (he loves the fine shreds of beet pulp, but has always left the chunks in the bottom of his pan.) He's also become exceedingly reluctant to go back to the pasture after being in the stall to eat a meal, culminating in a flat-out refusal to move a couple of days ago. I turned him around to go back to the barn, and he walked just fine. Turn toward the pasture, and he was planted to the ground. Ok, ok - I get it! You've obviously been trying to communicate that you are stressed, and I haven't been paying attention.
[a side note: it is the mare that is harassing him, biting him, chasing him, etc]
That evening, I put him into Rhio's pasture, which also includes 1 other gelding and 1 mare. Of course there was the usual sniff-squeal-chase stuff as the group was disrupted, but Rhio and Cricket have known each other for many years and lived together most of those years. The mare and other gelding are very mild in the pasture, and they all settled right down to eating. The next morning, Cricket and the mare were in the shelter, Rhio was standing in the alleyway, and the other gelding was out in the pasture (normal distribution for this group.) Ah! All is well... until I bring Cricket into the barn for breakfast. He didn't eat a single mouthful as he whirled and screamed in the stall, even banging on the door (this is SO not like him!). And the mare was calling back to him. Uh-oh. Forgot about that! Old man Cricket l-o-v-e-s the ladies -- at least some of them.
Performing a self-inflicted forehead slap, I realized two things - 1) Cricket has likely developed another gastric ulcer from the stress in the old group - I say "another" because he had ulcers when I first bought him, from living alone for several years, and 2) he gets velcro-attached to mares if they like (or even just tolerate) him and none of the other geldings care. So am I helping one issue (stress-induced ulcers from being harassed in the other group) but creating another?
What to do??? I much prefer happy horses, and Cricket's not a very happy horse right now. So far, he's still in the new group and things seem to be calming down a bit. Tonight, in fact, he's in a stall in the barn due to the wicked east wind, and the mare is still outside. He's eaten well today, and is perfectly content in the stall tonight with a gelding in each adjoining stall.