I believe any tormenting of any animal to its death should be held accountable as murder, unless if the death was a fast one.
murdering animals shouldn't carry the same penalties as murdering humans, that's handicapped. do we take bob the urban man on a road-trip to court when he runs over a deer and doesn't have the willpower to break its neck to end its suffering? do we lock up people who hunt with bows and traps? animals don't have the mental capacity of humans. certain groups, e.g. apes, elephants and toothed whales should get extra penalties because they've demonstrated an impressive cognitive capacity, but there is no scientific argument for saying that killing a cat should be treated as murder.
also "any animal"
Man Imprisoned for 5 Years after Killing Worm In Backyard