Ooooo! I'm new here and clueless, but here is a question to which I can actually make a contribution.

We've had a saltwater pool for the past 6-ish years. We have a mini schnauzer, that like your dog, prefers to drink from the pool. In the summer, he jumps down onto the first step and drinks away. During the winter, he runs out onto the cover and his body weight is usually enough to make some water flush up on top of the cover.

I specifically asked our vet if it him drinking the salty, chlorinated water was a problem. He said no problem at all. Which is good to know, because i'm pretty sure it would be IMPOSSIBLE to make him stop!