Is Your Horse Left-Handed?

Do you understand the natural asymmetry of the horse and its implications for saddle fit? 
Most horses are lefthanded or what we refer to as dominant on the lefthand side and it is usually very obvious. There are many theories as to what causes this predisposition. The German FN the governing body of riding in Germany even recognizes in its rule books that most horses are born with a natural asymmetry and that it is cerebral or determined at birth. It could be caused by the way the equine embryo grows in the mares womb. At least 70 percent of the thousands of horses we see each year are lefthanded while about 20 percent are righthanded and the remaining 10 percent are relatively even. I am of the opinion that asymmetry occurs in part because of domestication and due to the conditions in which we train and keep our horses. There are various theories on the causes of asymmetry in horses but I will focus on the issues that arise as a result.

Most of the horses I have analysed over the past 34 years were kept in stables or living on relatively flat pastureland and most had more musculature on the left over and behind the left shoulder with a shoulder blade that was obviously higher and further back on the left. In nature the trend may be to more evenly muscled horses but I have not dealt with enough wild horses to be able to comment on this with authority.
When working with horses humans seem to cultivate this affinity to the left we mount from the left lead on the left saddle on the left some horses are even distinctly uneasy when approached from the right. When two horses fight they can be observed turning their left shoulder to the aggressor. Often it is easier to canter on a left lead have you experienced this?
After the age of two the development of the horses skeletal structure is pretty much complete. Correct training may impact muscular development to help counteract natural asymmetry but this inherent asymmetry must be taken into consideration when fitting a saddle properly.
The saddle support area of the horses back begins immediately behind the shoulder blade at the base of the withers. The shape and position of the gullet plate in particular needs to accommodate any unevenness in the shoulder area. Its function cannot be substituted or