DressageStrider, I hope I’m expressing this clearly and correctly, but yes, we’ve been building my horse’s strength and stamina for the collected work over time. The sweaty back end indicates good hind engagement, but you are developing that through all the levels. As the collection increases, not only must the horse carry himself behind, but he also must lift himself in front. Again, this is developing through all the levels, but increases in difficulty the higher you go.
When his is really carrying himself (self-carriage) he’s working hard everywhere, not just in the hind end. He lowers his haunches, bends the hind joints more, and lifts his forehand, lightening in front. I suppose the extreme example of this is the Levade.
My horse is long-backed, so this collected work has been slow to develop and difficult for him. Also, he’s the first horse I’ve brought along to 4th Level, and I depend on my coach to guide me.
The lifting and lightening of the forehand is harder for a long-backed horse than it is for a short-backed one. So when he’s really working underneath himself and lifting his forehand, the effort is reflected in the sweat on the shoulders, withers and neck.
One other observation from my weekend clinic: Siegfried remarked on Figaro’s relatively steep shoulder – better for a jumper than a dressage horse. He will always lack the freedom and scope that a better shoulder might give him. Still we do the best we can.
I think different sweat patterns might indicate where a specific horse works harder due to conformation. It can also indicate incorrect work, as another poster said. Sweat along the bottom part of the neck (common with ewe-necked horses), indicates the horse is working the wrong muscles.