Cute, what kind of dog is that? My 8 month old terrier just noticed some corys in a lower tank last week, just sort of watched them. There are several tanks at eye level, the older guy never pays much attention to the fish.
I'm more concerned about them using the low tanks as a water bowl, my older terrier was trying to drink tank water that was coming out of a drain pipe a few weeks ago. A fishroom dog bowl seems to have solved that little problem, for now.