Re: RC: low potassium, ok sodium

[CMKSAGEHIL@aol.com]

In a message dated 5/14/00 8:48:10 AM Pacific Daylight Time, 
stepnout@swva.net writes:

<< The respiratory alkalosis horses develop from racing may be part of the low
 potassium (K+) picture.  The electrolyte picture is quite complicated and
 involves ion trade-offs in order to maintain pH, or acid-base balance.  My
 thinking is K+ is excreted so the body can retain H+ (hydrogen) to help
 bring down the elevated pH occurring during extreme carbon dioxide (CO2)
 loss.  That's just one aspect of the electrolyte scenario (and it's not
 quite the same in horses as in humans.)   Any equine exercise physiologists
 care to elaborate?   >>

More is also driven into the cells in this scenario--as was previously 
mentioned, circulating potassium does not necessarily reflect what is going 
on in the body.  I find it a bit worrisome that folks get the impression that 
whatever is low can simply be replaced by syringing in more of whatever it 
is--there are often very complex and dynamic mechanisms at work (as in the 
case with potassium), and if the body is madly excreting or driving it 
intracellular to try to balance pH, adding more could actually be harmful.  
This is why simply empirically adding electrolytes (although it USUALLY 
helps) can sometimes REALLY go awry.  I am especially concerned about the 
folks that describe adding potassium on a daily basis--if the horse is eating 
plenty of good quality roughage, I'd start looking for reasons OTHER than a 
deficiency in intake for low potassium levels...

Heidi