Re: electrolyte supplementation

[CMKSAGEHIL <CMKSAGEHIL@aol.com>]

In a message dated 98-04-17 09:00:41 EDT, mlinding@uoguelph.ca writes:

<< One needs to differentiate between the concept of 'conservation' versus
 what what is available to be lost (in either urine or sweat. If the
 electrolyte is not available, it cannot be lost at adequate rates to
 produce an optimum sweating rate for effective thermoregulatory cooling of
 the exercising horse.>>

With a good roughage fill in the gut, good parameters throughout competition
regarding gut sounds, hydration, etc., and on the occasions we have done
bloodwork, not a lot of depletion of electrolytes post-ride, I would have to
assume that my horses have adequate amounts available to be lost.  The fact
that I do not force supplement electrolytes would lead me to believe that a)
they get plenty from feed and free-choice electrolyte, or b) conservation DOES
work, or most likely c) both of the above.
 
 <<You noted, correctly (as I pointed out yesterday) that sweat electrolyte
 concentrations may decrease in horses as they become conditioned. This is
 primarily ascribed to the production of a MORE DILUTE sweat, i.e. more
 water with the same amount of electrolytes. Therefore electrolytes still
 are not conserved.>>

You are presuming that they are sweating 10 times as much, since the sweat is
1/10 the concentration.  I'm not sure I buy that.  Certainly fit horses sweat,
and need to sweat, but unfit horses also sweat copious amounts--perhaps even
more, as they are not as good at thermoregulation and often have more
insulating fat making it more difficult to get rid of body heat.  If the
VOLUME is the same, then the more dilute sweat most certainly represents a
lower electrolyte loss!
 
 <<When you think about it, it does not make good sense to try to conserve
 electrolytes at the skin, because this will impair the ability of the
 horse to sweat and produce related heat stress problems. What may appear
 as 'conservation' may be an inabilty to provide the sweat because the
 water and electrolyte reserve is not adequate.>>

It makes good sense to conserve electrolytes everywhere possible.  As long as
the sweat VOLUME is adequate, there should be no impairment whatsoever to
thermoregulation.
 
Please note that I am NOT stating that supplementation at appropriate times is
not needed.  Rather, my point is that the horse will do best if his own
mechanisms are allowed to develop to the most efficient state possible, at
which point one can (and should) add electrolytes if he needs them to maintain
the status quo.

Heidi