These people are going to drown a dog, to show how easy it is to drown? That's not legal. It also doesn't make much sense, but never mind that now. Don't tell us, tell the Humane Society, Police Dept., etc. in your area. Heck, call PETA, not that they really care about animals, but they could use some could publicity.
I know this is off the topic but speaking of PETA I heard on Fox and Friends that these wackos either have or are planning on filing a suit against the NCAA teams who have the word cock as in "Game Cocks" because the states where these teams are located (sorry I'm not a basketball fan) have outlawed cock fighting.