We're boarding 2 horses, quarter-mix somethings, a gelding and a mare. We don't know too much about horses, and the owners hardly EVER come by.
Here's what's happening: the gelding is 7yo and spunky and a bully. He follows the mare, won't let her eat grain or hay unless we separate them, etc. He just bosses her all day long. They're in a huge pasture, so it's not like he doesn't have enough grass to be happy. Tonight I saw him biting her. She's standing there eating grass and he bites her for no reason. She hollers at him pathetically but he keeps at it . She's had low weight issues, so when we do supplement their feed, we have to feed them separately or she won't get her share.
Is there anything I can do about this behavior of his? If I get another water trough, I could put each in a separate pasture, but don't horses like companions, even if they're mean?
Did the mare move off, and he pursued her? Does he leave marks when he bites?
At first blush, this seems like a no-brainer, but I'd prefer to see them in action before I pass judgement. You say you don't know much about horses, would you be able to tell the difference between a bite and a nip? Biting to drive the mare away is one thing, play-bite "flirting" is another. Horses can be very vocal under certain circumstances, and loud! Not every squeal is a sound of pain or distress.
Sounds to me like this gelding needs a playmate or job with which to work off his excess energy. He's not necessarily bad, more likely bored.
At any rate, the mare does need some peace and quiet, at least when she's eating. I'm with Kelly G in being concerned about ulcers. I'd also like to know why this gal has "weight issues," - Quarter horses are usually easy keepers (meaning that they can almost stay fat on air!) Things like teeth and worms come to mind, although being pestered by another horse can also interfere with the ability to convert forage into fat. Sometimes with horses, you really have to put on your Sherlock hat and get to the root of the problem, to find the solution!