I have been trying to find info myself, since we chatted about it, but I have no news..how weird. Do you think you can distract him when he is doing it?
Ona adifferent note, is he still on raw food? Dogs on raw do not drink very mouch additional water at all, they simply do not need it as their food is not dried/processed. That might be why you don't see him drink water at home. My dogs don't and they are on raw so I did some research on that and that is the answers I found..
Otis also detest drinking out of a metal bowl, he will eat out of one but not drink, so I changed bowl to ceramic and he now drinks better, yet very rarely.