Did you read that bit in the March edition of Equus about that squeaky, grunty sound that geldings make? The Equus consultant who answered the reader's question claims to know. She said that it is likely made the same way as when little boys stick their hands in their arm pits to make fart sounds. What?!
Apparently, when a gelding's crusty doodad bounces around inside the sheath, out comes that grunty, squeaky sound. She said the creation of the sound involves "a moving object, some air, and a semi-closed space." Huh?!?
Okay ... so I ran this by my vet when Speedy G was there for his annual spring visit. She said that yes, that is a possible explanation of where the sound comes from. The Equus consultant pointed out that cleaning the doodad and sheath can reduce irritation which allows the horse to move in a more relaxed way which can eliminate the sound.
The dressage connection? ... well, seems fairly obvious since relaxation is the second tier in the Pyramid of Training.
And with that, here is a snippet of Speedy getting his doodad cleaned.