It isn't remotely analogous.
Perhaps. Maybe had he quickly decapitated the puppy, it would have been more humane. But if he did it for fun...well...
I'm not trying to get in a pissing contest. The bigger issue I see is that animal rights whackos love these kinds of cases. It's obvious we have endowed certain groups of animals with more rights and privileges than others and I have little faith in our politicians to make clear distinctions.