assuming your pool is chlorinated, I would limit the time he spends in the water.
It can dry out his skin and cause itching and bald spots.

A friend of mine went through this the summer of 2010.  Her dog swam with the kids everyday and developed the symptoms mentioned above.
She took the dog to the vet who put her on a special diet, gave her steroids and sold my friend expensive shampoos and rinses.  They were sure it was an allergy or worse and the vet bill was around $500 when it was all said and done. 
I tried to tell her it was too much time soaking in the pool water.........But apparently, since I have not been to vet school......yes I'm a little bitter.
After the pool was closed up for the season, the dog's skin issue cleared up.  imagine that.
sigh.......................

A pool with a salt system uses the salt as a disinfecting and oxidizing agent in a similar manner to adding chlorine.  It is a form of chlorine just like chlorine tablets only automatically added.  I would limit drinking pool water as Chlorine has been shown to cause cancer in people.  Most municipal water systems have chlorine added and it can be hazardous to people as the high Nitrate levels are in our water. 

Jim