Horse Blankets and Dressage, you ask?

For someone unfamiliar with horses and anything associated with horses, the word dressage might conjure up a few other images besides that of its true meaning.  One might wonder if it means clothing.  How absurd to think of a horse wearing clothing!  In a sense, horses do wear what you might consider horse clothing.  I suppose you could say its horse blanket is its clothing.  Although it could seem comical to imagine a horse in a pair of jeans or a tuxedo!
Could dressage mean bandages?  Horses do, after all, require medical attention at times.  They get cuts and scrapes just as we humans do.  Horses don't wear the same types of band aids as people, though.  For one thing, there is all that hair!  People can, however, use a certain tape on their wounds similar to the tape used to cover a horse's wound.  It doesn't stick to the hair but sticks to itself.

So, what does this term 'dressage' mean?  One dictionary interpretation is horsemanship using slight movements to control the horse.

"Okay," you say, "what does controlling a horse have to do with horse blankets?  It isn't as though you can use the blanket to apply his brakes or have him turn.  You won't find blankets listed as part of the requirements for dressage shows or in the lists of dressage supplies sold.

A list of dressage supplies would include things like fleece or velvet pads, girths, dressage leathers, boot, breeches, and coats for the riders, snaffle bridles, double bridles, stock pins, brow bands, cones for the course, bits, and saddle carriers.

So, let's get to the part where a blanket is an important item should you decide to enter the world of dressage. 
A comfortable horse blanket that fits the horse's needs, size, and the climate is an essential part of owning a horse.  When you prepare a horse for dressage, you wouldn't want your improper use of a horse blanket during the care of your horse to interfere with your training.  An uncomfortable horse makes a less willing horse.  Perhaps, you could say, a horse with attitude!  Obedience in dressage is essential.  It's a horse-related sport.  Showmanship is the key, and attitude affects showmanship.  Attitude is affected by how well you have cared for your horse, which includes use of the proper blanket.
Suppose you wear socks that cause blisters on your feet, or maybe you use detergent that causes a rash when you wear your clothing.  Maybe your shirt is too tight and restricts your movement and cuts off the circulation or inhibits your movement because it is too large.  Maybe you are forced to wear a wool suit while the weather is 110 degrees!  If you are continually subjected to these abuses, it will affect your attitude and your performance.

Hence, the horse blanket will play an indirect part in your dressage, which involves ease of control and fluid movement.  Improper fit of the horse blanket results in friction-related injuries.