I saw an ad for a horse for sale, and this horse was buddy sour. The seller recommends keeping him in a paddock alone to fix this. I think this is a terrible idea, although I know it is a common approach.
Here is my buddy sour horse story. My 27 yr old pony hurt his back the same summer my 3yr old filly injured her rear fetlock. She needed turnout for a few months and so did he, so I took them to my house where I had a 1 acre pasture with a large run-in stall. After a few months the filly was better so I moved them back to the farm. When I went to get her out to ride I quickly learned they were extremely buddy sour.
How did I fix it? I kept them together constantly. If I rode her I brought him in. If I worked with him I brought her in. Whenever one of them left the pasture they left together. At first I would just let the pony follow loose because he was certainly not going anywhere other than where the filly did. And guess what? After 4 months they aren’t buddy sour anymore. I can bring either one over and after maybe 1 or 2 whinnies they go about their business.
How does that work? Here’s my theory. Buddy sourness (barn sourness too) is rooted in discomfort and anxiety. They want comfort and familiar, safety. It is a sign of a horse who is experiencing stress, whether it is fear, pain, or a lack of having their needs met. Get them comfortable and well adjusted and those problems fall away.
My pony and my filly were both under a lot of stress, already being injured and in pain, then being moved from a large herd to a place where they were the only 2 horses. They found safety together. By the time they moved back to the farm they saw each other as their source of comfort. When I took the filly in to ride alone I took the pony’s new sense of security with her. When I took him too and put him in a cozy stall where he could watch her being saddled it got him used to a tiny bit of distance in a way that wasn’t threatening. They both got yummy 3rd cutting hay to sweeten the deal. Pretty soon they looked forward to the time they came over, got separated and got their yummy snack before they got sent back out in the cold to eat 1st hay in the lean to. Soon their comfort was coming from somewhere else, and their confidence was independent from each other. By the time I tried leaving one in the pasture they didn’t need each other anymore.
It is also important to note that the pasture I was leaving them in was a safe place that had adequate food, shelter and safety. A buddy sour horse who is not having their needs met, or who is under constant stress (being agressively harassed by a dominant herd mate, chronic pain, inadequate shelter, inadequate food, etc) is unlikely to have the same results, due to the fact that they are unable to achieve that sense of security necessary to be confident alone. My first step with any behavioral issue with a horse is to ensure that their basic needs for food, shelter, rest and freedom from pain have been met.