I would like some information on this topic as well. I have a 5 year old mare and a 20 year old gelding and we have to turn one of them out in the pasture if we are going to ride the other one so they won't hurt themselves in the stall. Any advice and/or suggestions would be great!

I'd love something on that subject too!
My 20 yo mare has become quite agitated when her (only) stable mate - also the flockleader in their tiny flock) leaves the stable to be ridden. It's become worse in the past year.
From my own experience, I can recommend that the anxious horse is exercised properly before being left alone, as that certainly seems to help my horse a good deal, but I know fair well how that isn't always possible.

Just as Monty suggests in Q&As, changing spaces and company works great for seperation anxiety. If your property allows, start with smaller distance, even so your horses can still see each other and then gradually increase the space till they cannot see or even hear each other.
I have a mare that normally lives in a pasture with two other horses. She came form a race track and sudden pasture space and opther horses were the best thing for her and I could just see the problems with anxiety. I started from the very beginning: every day I tookher out the pasture and put her somewhere else on the property, by herself. Sometime it would be closer to the pasture so she could see her buddies, sometimes further away, sometimes by different horses. I kept the routine alive also by doing different things with her: one day it would be just changing place, other I would take her for a ride, next time I would give her bath, sometimes we would go for a walk. I also changed the time of the day. These days I can take her out anytime and she doesn’t get upset. Her friends will call her for a few minutes but then they still have each other. We do similar thing with the other two. So… even if it takes a little bit of time in the beginning, it is worth it – horses learn how to separate and live with it:).

Kasia

Good to know this is not just a problem I have. My 8 yo Quarab mare is fabulous as long as another horse is with her, seperate her from the other and she becomes almost hysterical. I know in her past she was left alone to fend for herself for quite a long time and its very difficult to do anything with her if she is more than a few yards from my other horse. There are some good ideas on here for possible solutions and I will try some of them.

Thank you Kasia for mentioning the Q&As available to Uni students about separation anxiety, buddy sour and barn sour. The Q&A tab, above, is a great tool.

First, click on the Q&A tab and think of a keyword that might be general to your question. Type it in the search box and see what you get. The search sorts by video content, forum and archives - very thorough.

Monty has hundreds of answers on the Q&A about a variety of subjects.

I too would love to see a video on how to deal with horses that think they are siamese twins! I have an 8 year old gelding and an 8 year old mare. The gelding was by himself in our pasture since he was 3, and just a month ago, we introduced our mare to him. They hit it off great, but now, any time we go to the pasture to see them, our gelding automatically goes on guard! He will get between us and try to block our access to the mare, and of course, the mare just hides behind him. They haven't gotten to the point of being dangerous, but it is quite exhausting to have to attempt to catch the mare to put her on a lead line. I have successfully achieved join-up with the mare, but the gelding has proven a bit more stubborn with it. He gets highly anxious as soon as we enter the round pen, and no matter how calm I am with him, he gets geared up and breaks a sweat. Unfortunately, we have no stalls in our pasture, so separating the two seems almost impossible without tying one of them. I hate to do that. I would love to see a vid on the anxiety issue, and also, something about how to catch a horse that wants to run from you, even after successful join-up has been achieved!