Hello everyone, long time lurker here hoping for some advice.
Two months ago I got a 15 year old welsh D/arab cross on loan, with the possibility of eventually buying her. She spent most of her life competing until she retired due to injuries summer of 2013. After that she was sold as a brood mare suitable for gentle riding. Her current owner tried to breed her about a year ago, but it wasn't successful - according to the owner, the mare simply didn't want to/didn't accept the stallion.
I've had issues with her from the first week. She was a bucker in the school, which eventually improved (but didn't disappear) with determination and her being shod on her fronts. She was in good health according to the owner, and I had her back checked which was also fine. The other incident was after we popped a tiny jump out in the forest a couple of times, and she got so worked up she took off in an uncontrollable canter for one mile before I lost my stirrups and fell off on the last stretch home. I didn't manage to stop her no matter what I did.
End of February I moved her from a bigger DIY livery stable where she was alone in her field, up to a friends private stable, where my horse is currently pastured with two shetlands - a 7 year old mare, and a 26 year old mini shetland gelding who has always been very, very low in the pecking order. At first everything was fine and dandy between them all, the 7 year old bit my mare a few times but there was never anything serious. Problem now is my mare and the gelding. My mare started showing food aggression towards him, chasing him away, nipping him and such - but never really around me, only my friend.
Today was the worst by far though, and I have never seen or heard about something like this.
My friend came at lunch to put up some new fencing where the mini shetland had been escaping into the neighbours lovely, green garden, and thus he had spent the night and half of the day inside in his stable. She let him out while she was in the field.. and my mare went absolutely berserk at him the moment he stepped through the gate. She galloped towards him, ears back and teeth bared, while he tried to escape from her running along the fence. She went after, pushing him up against it while biting and throwing her head. He got away, cantering desperately towards a fenced off area with machinery, planks and whatnot, and crawled under the lowest electrical rope to reach safety.. and my mare sets off at full speed after him again, JUMPS the fence which over 4 feet high, in order to go after him! My friend is shouting and going after her with a lunge whip, but my mare just continues biting and kicking and pushing the gelding up against the stone fence. Somehow he thankfully manages to squeeze past her, reaches the wooden fence going in to the neighbours garden, and breaks the lowest plank to crawl into their garden, leaving the mare cantering around the machinery and throwing a proper fit.
The gelding is very old and so small, and he has never, ever done anything bad or challenging to anyone, he always moves off and stays away. I can't fathom why my mare would go to such extremes to chase a horse like him, and actually jump high fences just in order to continue tormenting him! That can't be sound behaviour, can it?
Aside from these issues she's a lovely and well-mannered horse around me, she listens well, learns fast, and is brilliant with voice commands. But all of this is obviously a very dangerous situation for everyone involved, horses and people alike, and at the moment I'm set on the possibility of having to return her.
This turned out way longer than expected, so kudos to anyone who is willing to read this.
If anyone got any ideas or thoughts about whats going on and what to do, I'd love to hear it.