Actually there is no difference in the
sweat secreted by an unconditioned/young/unfit horse and a fit
one. There was a pretty good article on this (Equus, I believe) some time
ago. If I remember correctly, the foamy sweat is due to an accumulation of
contaminates in the sweat glands and on the skin/hair coat. The more he sweats,
the more he washes away the contaminants and the more "clear" the sweat becomes.
Here's a "quickie" by Gayle Ecker on equine
sweating and electrolytes:
I've found that an unconditioned/young/unfit
horse will sweat foamy, salty, thick and sticky sweat. It drys crusty
and salty on the skin/hair.
As the horse gets in better shape the sweat
begins to get cleaner and more watery. A really fit horse's sweat
hardly tastes salty at all, and leaves almost no residue on the hair, just
wet.
Gayle
Ecker, who has been studing electrolyte loss in endurance horses since the
late 80's and probably has looked at over 5000 endurance horse's blood told
me one time that even in training horses can loose significant electrolytes
and they don't acclimate to that loss - that is they don't get better at not
losing them.
