Spooky horse and sudden bucking and rearing

Question
I am a very new horse owner, I have had this horse since the beginning of July. She is ridable and i was sold this horse under the term of being "green broke" and " needed to be finished and that I needed to desensitize her to her being so spooky. I have ridden the horse bareback several times, and I have also ridden her in a saddle and she takes to leg pressure and commands fine. then one day i saddled her up went out to the field went to get on and that was the day she reared and bucked me off. she broke through my fence and due to me being injured she was kept at my neighbors property with her horses. I decided this horse is too much for me to handle and i don't have the experience needed to handle her. So I decided to try to sell her and let the potential buyer know that I have been bucked off. originally i thought it was my fault that i must have not tightened the saddle down fully or did something incorrectly with saddling her. well i had a girl come check her out and she saddled her up and went to get on and the horse bucked and reared with the girl. until the girl gave up and come out of the saddle. i don't understand how i went from having a horse i could ride around my back yard to suddenly having a horse that is bucking and rearing and has no respect for the person and she totally disregards the bit as far as trying to control her when riding and when she rears and bucks she could care less about the bit. what could be the factors involved to make her do this?

Answer
The horse could have been drugged, some drugs will last for quite a while.  Could also have been given something to mask any pain it was feeling.  And also could be the fact that you were not trying to make her do anything that didn't suit her.

By that I don't mean heavy training, or work, but that for the short time you may have ridden her around in back yard, it suited her right then, as she knew you weren't going to go far.  Now that you are wanting to ride her, she is showing her true colors.

I will approach this several ways since I am not able to see the horse.

First thing is that this horse has never really been trained, and has not a clue what you are doing.  If she is green broke, it could be just luck that she seems like she understands leg pressure and commands, rather than her really understanding them.

It could also be related to pain issue, broken jaw, broken withers process, broken ribs, cracked vertebrae, all sorts of things could be wrong.  Without a vet workup?  No way to tell and there is a good chance that the vet might miss something even then.  I have seen that happen.  Could also be the saddle doesn't fit, or is too far forward, or the skirts are too long.  It doesn't have a back cinch does it?  Pain from an ill fitting saddle can cause this too.

She also could be just a rogue, ill tempered, and barn sour, along with mare.  That has a lot to do with this type of thing at times.  And if she is only just started under saddle or to a bridle, then could be the bit didn't fit right, or too tight over poll.

Whatever is going on, the fact that she is willing to rear in addition to the bucking would be enough for most people to get rid of her.  This type of horse can not be handled easily by anyone other than a person who has dealt with them over many years.  This is the type of horse that can get you killed quite easily.

A lot of the respect issues come from handling a horse on the ground in the wrong way, making a pet out of them, or not understanding the dominance horses exert on each other and us, if we let them.  If she is a pushy type, or one that "demands" things, that can lead to many problems too.

Also, she has been with you now just long enough to get the feel of the place, and has settled in.  Many times about a month along, a horse will try itself some.  More than that going on here, and I feel you may have found the reason she was for sale.

I've seen horses like this, and I would not recommend that you try to do anything with her, as she will hurt you, and possibly kill you.

I would talk to the person you bought her from, if you can find them, and tell them that this horse is dangerous, and you want them to give you your money back and take the horse.  Do not let them talk you into a trade either.

Many mares are very hard to handle when in season, could be what is going on here, but still can get you hurt.

Horses over time, if let to get away with things, like acting threatening when you feed them, pinning their ears at you, ignoring you when they want to graze, or turning their rear ends to you, will get like this to some degree, and if left unchecked, can get to be what we call barn sour.

Get an older gelding, from someone reputable, and get rid of this horse.  It will only get worse I am afraid.