[fatnotlazy]

But what if someone holds the dog under water (probably would have to be someone very strong or two or more people).

[RobFromGa]

But what if someone holds the dog under water

Then they'll go to jail too. This is a stupid radio prank people they aren't going to drown a dog. But they do have people talking about drowning.

SO they've made their point and probably performed a valuable public service.