What Can We Do For Our Dog That Drank Some Dirty Water?

I would have this dog examined by a veterinarian immediately. 
If this is gastrointestinal upset you can try giving Pepcid--the dose is 0.5 milligram per kilogram by mouth given twice daily.  Offer boiled chicken, boiled rice, canned pumpkin, or puppy food.  Try feeding Pedialyte or flavoring the water with a small amount of chicken broth or vanilla ice cream.

Have him nibble some grass. OR, if you suspect for the worse, call poison control. My puppy got into some rat poison once and they had us feed him a spoon of *I THINK* that kind of alcohol that comes in a brown plastic bottle. He turned out fine when this stuff made him purge his stomach (barf).

Calm down its a dog they drink dirty rain water just give him a few days maybe hes just tired