putting horses together

Question
My name is Stephanie and I am 46. Have owned horses for a little over a year. Jigs, is a draft/cross and he is 4. Cowboy, is a paint and he is 12.
I board with two other people that have 2 horses each. Scotty is a ex trotter and he is 26. Jenny is ex trotter and she is 24. Chipper is a TB, and did some racing so I am told, he is 27. And a other Cowboy that is also a paint and he is going to be 3 in May.
My or I should say our problem is all the horses have to be put in the same pasture. My Cowboy and Jigs shared the same pasture with the other Cowboy and Chipper for 5 months and got along well. The owner of Chip and Cowboy separated them from mine, because her horsed wouldn't come to her. She said my cowboy would run them off. I never had a problem with getting the horse to come to me. Anyway now my horses, Cowboy and Jigs share a pasture with Jenny and Scotty and they get along really well. When Chipper and the other cowboy were brought in with Cowboy, Jigs, Scotty and Jenny, all h--l broke loose. My cowboy tore Chipper up, chased him and bit his hindquarter.They were together for only about 6    hours. Chipper and the other Cowboy were taken out by their owner. Chipper and the other cowboy are stall ever night my matter what.  After about a week,  I put Cowboy and Jigs in another pasture with Chipper and the other cowboy. Cowboy would still run Chipper off, but not as aggressively as when they were all together. We did that for a couple of days. Then we added Scotty to pasture. All seemed fine. So now we have all gelding together. Jenny was added and Cowboy started after Chipper again to the point that Chipper ran through the fence and kept on going full stride. What I don't understand is Chipper was no where near the other horses. He would keep to himself. Cowboy would go after him for no reason. Chippers owner seems to think it is all about the mare. But Chipper is no where near the mare, pays no attention to her. Is the mare the problem? What should we do?
Thanks,
Stephanie

Answer
I am lost with all the names and horses, but that does not matter.  This is all perfectly normal behavior.  Understanding herd behavior enables us to use that to train them.  In the wild, there are no geldings, so people get involved and we create problems and then want to blame the horse.  Not saying you are doing this, but you and others need to understand where the horse is coming from and why they do what they do.

It is hard to explain on an email, but all herds have a pecking order and every horse is either higher or lower than another horse.  You and your horse is it's own herd and you must be higher than your horse.  Your horse will test you to see if you are strong enough to be in charge, just like they do in a herd.  Nature programs horses to test leaders to ensure the survival of the herd in the wild.  By making sure on the strongest and smartest is in charge, it ensure that only the strongest and smartest will reproduce and have offspring.  

Your horses are doing this, the problems is in the wild there are no fences, so the horse would push the lower horse and he would run off with no problems, when we cage up horses we create the problems.  I would guess that this horse ran through a fence in or near a corner, corners are bad for horses and they trap themselves.

Read my horsemanship page and I discuss herd behavior.  Mares in heat may intensify the problems, but the pecking order would still have to be established with or without mares.

The worst thing we do is constantly change the herd.  Taking horses in and out, adding new horses and taking away horses only disrupts the entire herd.  Every change causes all horses to re-establish their pecking order and try not to be the bottom horse.

If two horses are the main problem, I would work those two together, make them more worried about me so they would not worry about each other.  I would tie the horses together for a few hours and make them stand next to each other, it they fought or tried to fight I would put pressure on them with plastic bags and make them more aware of me so they would learn to ignore each other.  Another option would be to put them in the a round pen and let them chase each other until they worked it out.  The horse that is running is not respecting the the horse chasing, so the horse chasing continues to chase to show his dominance, as soon as the lower horse shows submission and keeps his distance, the problem will go away.  This is a learning process for the horse.  Normally the older horses will educate the younger and teach them to yield to the higher horses.

Not sure if this helps,

Rick