Very few horses or humans would be totally symmetrical and I doubt very much that this is causing her problems. If the difference is only a half inch then corrective shoeing would possibly help but I believe it is more than that.
Below is a theory I wrote some time ago and a method for testing if a horse is misaligned. As I say in the article it is very rare for a horse to go wrong in the spine, if correction is needed there then 99% of the time it is to put right something another chiropractor put out in the first place.
Many times a horse get the label as being naughty, bad tempered or just plain difficult when he is uncomfortable or even in pain.
Stiffness in one direction or difficulty in getting him to canter with a certain lead. Swellings such as thoroughpins, spavins and curbs are all signs that the horse is not carrying his (and the riders) weight correctly. Some of this can be due to poor conformation, over working a young horse or, because the animal is misaligned.
If you liken a horse to a car, in that both have four corners. You can drive a car when the tracking is out but, the steering is not as good, braking can lead to skidding or not stopping in a straight line and the tyres wear out unevenly. It is much the same with a horse. If he is misaligned then he will move to compensate where he is ‘wrong’ This leads to signs of strain as mentioned above. It can also lead to uneven wearing of shoes although some of this can be the camber of the roads.
Such is the honesty of the horse that many will carry on doing as we ask and, should they object for some reason or another, then they are often whacked or driven to doing whatever when, all the time they are trying to say ‘That hurts.’
The horse that moves around when we go to saddle it or, is difficult to bridle, is usually saying that something is uncomfortable. With the ill fitting saddle it is no good using extra pads as this can make things worse. After all, if you have a pair of tight fitting shoes that hurt, you do not wear an extra pair of socks to make them fit better!
I fully admit that I have a ‘thing’ about backs but, I am more often right than wrong with an assessment. Over many years, I have found that it is rarely the actual spine that misaligns, it is more likely to be a shoulder or hind quarter that goes out of true and, to compensate, the diagonal quarter will also misalign to compensate. There is no telling as to why they go wrong, could be just slipping in the field, falling, or getting cast. You name it and they can do it. Often problems in the body have come from misalignment of the neck or jaw.
Simple tests to see if your horse is square.
Head and neck:
Take a carrot or other tidbit and standing by your horses shoulder see if he can take it from by his elbow and from between his front legs. Gradually stretch the distance so he is taking it from near his hip. Do this both sides.
Pick up the foot and stretch the leg forward as far as it can go. There should be no resistance and both legs should reach the same distance.
Pick up the foot as normal. put the hand nearest the horse over the forearm and hold the canon bone about half way down so that the hoof is flopping down. With your other hand just raise the hoof so that the heel is against the forearm (horses) the centre of the frog should be central to the forearm. It is important that you do not pressure the hoof up nor move it so it is central, just let it come up naturally.
Back/spine: any flinching or juddering at the withers is a sign of tension.
Run your finger and thumb firmly but not with undue pressure about an inch either side of the spine, any flinching is tension.
One of the easiest signs that something is wrong is hen a horse is good for the farrier on one hind leg but not the other, especially when the leg is held up higher.
There are several tests for misalignment - stretching the leg out behind, he should be able to do this easily both sides.
Pinch you thumb and forefinger together and standing to one side, place your thumbs and fingers about 4” either side of the dock but well above the top of the tail, half way down his quarters and exerting pressure, run the fingers down the muscle line to about the bottom of the dock. The horse should arch is back in a straight line.
A horse that is very stiff in the dock and clamps it down when you try to bandage it or wash the dock is also misaligned.
There are as many ways of testing the horse as there are for them putting themselves out of alignment! By using applied kinnesiology through a second person, it is possible to pin point not only exactly where the problems are but also which way they have misaligned and then to correct not only the skeleton but also to alter the muscle memory. Once a horse is squared then there is no tension in any of the points where they were before. A horse that has been wrong for sometime will have to learn how to use himself correctly because he will be use to going a certain way to save himself.
If a chiropractor knows their business and not only realigns but also alters the muscle memory, then only one treatment is likely to be needed with a check up to ensure that all has stayed corrected.