The first possible cause of your mare’s behavior could be physical pain or discomfort. Ulcers and other ailments to the digestive tract or reproductive organs could be an underlying cause for the behavior you describe. It is therefore critical that you consult a veterinarian as a first line of investigating this problem. Once you rule out or address possible physical causes then you can address the behavior with training, with the help of a toothbrush.
It is now possible to buy electric toothbrushes almost anywhere. Get one, and tape it to a bamboo pole or similar light stick of some sort. Make it long enough so that you are completely out of any danger. I recommend the use of the Dually Halter so as to educate your horse to stand while you are out of the kick zone. Stroke your mare first with the toothbrush off.
Once you have her standing allowing the toothbrush and the pole to touch her everywhere, then turn on the toothbrush and begin at the wither. Continue to work broadening the area you touch. It may take some time but every horse will eventually learn to like the massage effect of the vibrating toothbrush. Give her a good reason to trust the sound as well as the vibrating movement.
This mindset must become part of your horsemanship before you will be completely successful with any challenge that your horse exhibits. One must be prepared to take some time with these challenges, accomplish a diminishing of the fear, and then habituate your horse to accepting the frightening object. Enter this with the knowledge that it will work and you will be successful.
Horses can read your pulse rate, your adrenaline levels and any level of anger that you have within yourself. Try, at all times, to set up your procedures so that you are in a safe place and you can keep your adrenaline down and have no anger. Once you have done this, then I recommend that you smile, go about your work, and watch how successful you will suddenly become with your horse.
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