HELP-up and over she will go!

Question
I just recieved a 5 year old mare from a horse breaker/trainer. I am given a horse (loaned)to ride and keep until he needs it for polo or to sell etc..I ride his horses and spend a lot of time handling them.I am a horse lover and a lifelong owner/rider and experienced equestrian in both english (hunter/jumper) and western.  This young mare, 5 years old, that I just took on last week has a bad habit of rearing up and over backwards.  The trainer has his method of tying the mare while standing to prevent this mechanically. I dont want to experience this while riding. I have been lunging her and tiring her out pretty good before jumpping on. How can I work this dangerous quirk out of this mare? Is it possible that the horse is always going to react to stress in this over-the-top manner?     thank you,Sarah-Hawaii

Answer
Sarah,

    Rearing is a serious problem and one that I encounter quite frequently in some of my own horses.  The first thing to consider is the why, "Why is this horse rearing?"  To help you answer this, I will need to know what her demeanor is like when she is "normal."  At what point does she decide she needs to go over backwards?  Is she routine with it,meaning she does it every time or is it an every once in a while problem?  Is there something that maybe you or she is doing that will trigger her violent reaction?

   Unfortunately, a rearing horse is a very dangerous and very serious threat to personal safety, not only to themselves, but to handlers as well.  Rearing is a sign of defense, so in essence we must teach the horse to understand that handlers are not something they must defend themselves from.  A good question from here would be, prior to your handling, how did the trainer/breaker treat this horse?  What did you notice when he was handling her?

    To get you started however, remember when a horse behaves in a way that is not acceptable, we have to make that line in the sand very clear.  It sounds to me in your question like the mare has accepted her bad behavior as the norm, but it can be fixed!  Remember, when the undesirable behavior is displayed, punishment must "fit the crime" and must be delivered very quickly, on the spot.
    
    One trick I use when dealing with this dangerous habit is to get to one side, get out from underneath the hooves, and pull back towards the hindquarter.  This forces the horse's hindquarter to free up, thus meaning that they are unable to hold the rear...remember, a horse can only successfully rear when they can do two things: 1) come to a complete stop and lock up their rear ends and 2) when they can get their head up.  (This is why your trainer friend ties her head down).  

    When the horse is back on all fours, I immediately send them into a longe.  I ask for the trot, the canter, the walk, the whoa, turn them and as again.  Usually this starts to change the behavior immediately.  Get them thinking, that is the point, get the reactive side of their brains to be dormant by constantly challenging them think about what they are doing.

    Until you can get back to me with the other answers, if you are riding this mare,  I seriously recommend the use of a smooth snaffle bit and a running martingale.  The martingale, when coupled with a smooth snaffle is not painful, it does however,  allow you to control the position of this mare's head as it relates to your safety in the saddle.  With the mare's head in a lower position: 1) the mare will be working off her hindquarter, which means she has a less chance of locking it up, and 2) she wont be able to get her head high enough.

    If you have done all of this and she still refuses to stop rearing under saddle: When you use the martingale, deliver a hard heel to both sides and push her forward or if you are riding without the martingale, pull sharply to one side, pulling the rear off balance,forcing her back to all fours.

    Be careful!  Let me know how this works out for you!