Problem Horse - Rearing
I have been working with a 5 year old quarter horse mare for about a year now, and thought her issues were resolved, when suddenly, within the last month, another habit popped up that has me concerned.
First a short bio on the horse - she was an orphan that was brought to the facility where I work as a yearling. She received a solid start, went into training and has been ridden on trails, to a show, trailered, stalled, shoed and on and on. She's been making big strides towards being a good little horse with a lot of try and a love of pleasing.
However, within the last month she's started a bad habit. I was told by a friend who rides her that she began rearing. Having never seen her do this, or had her do this while I rode her, I asked her to show me. Sure enough, as soon as the riding got underway and the rider asked her to try something new, the horse shut down, backed up, and stood up. Now, this backing up when confused was typical, but once you would walk her forward, ask again, and she understood it, she didn't do the behavior.
I asked the young lady to hop off and I wanted to see what was setting the horse off, so I got on to see if it was mixed signals, bad attitude or something else. Again, she decided what I was asking was too hard and reared. I got off, and hustled her around, using groundwork to get her attention. I suggested going back to basics - getting the horse's respect on the ground before getting back on her to curb the behavior.
Any other ideas what to do? It seems the issue has been diminishing since we've taken her back to square one, but I was curious to see what others thought of this. Thank you to any and all advice.