It's probably a good idea to check with the vet but I don't think there is too much to worry about. Drinking water too fast especially after exercise can upset a dog's or a human's stomach. Our dogs sometime have a single or more case of vomiting and unless it is something that does not stop within a an hour or so we don't worry about it.

Dogs are kind of like people, some seem to get upset stomachs more often than others. Our Dazzi has had some bouts with her stomach where I can't think of a time, Snoopy has been sick to his stomach; and I am don't think Taggert has had much of a problem either.

Dazzi used to chew on one of those braided knotted ropes - one night - very late at night like around midnight - she kept getting sick. She acted like something was stuck in her throat. With Christy holding her, Carl forcing her mouth open, I found a string stuck between two of her back teeth. She would swallow it but it wouldn't go down and it would gag her. We were all glad to find what was making her sick and when I pulled it loose her stomach settled down quickly.