I use ceramic small bowls...one thing that we were told by our trainer is that we should use bowls so we can see how much water they are drinking to see when they might need to go out and go potty...so I like to be able to see how much he is drinking..so far he drinks about half of the bowl in a day...but I am sure the older he gets the more he will drink
I would worry about him chewing on the plastic...