Given the abrasive nature of the dog's tongue and the anti-septic nature of its saliva, if the fountain wasn't clean before the dog used it, it certainly was afterwards.
But it doesn't really matter if the outside of the fountain is clean or not as long as you don't actually put your mouth on the fountain. All you care about is the water pipes inside the fountain, and those are just as clean as water pipes any where else.
> All you care about is the water pipes inside the fountain, and those are just as clean as water pipes any where else.
I don't see why they would be, especially on the end close to the outlet. I mean, lots of water pipes don't have an open end, facing upward and at angle, exposed to the outdoor environment. Sure, water fountains have shields over the outlet to minimize environmental contaminants entering them, but the fact that they are in a position to need them is an issue.
Now, it may be that in normal use the additional contamination doesn't significant additional danger (I'd expect this to be true inversely with frequency of use, all else being equal), but I wouldn't think it would be "as clean as water pipes anywhere else".
But it doesn't really matter if the outside of the fountain is clean or not as long as you don't actually put your mouth on the fountain. All you care about is the water pipes inside the fountain, and those are just as clean as water pipes any where else.