Why does Ozymandias kill Bubastis in watchmen?

ok this is something that's been bothering me for a while and i don't understand. but why exactly does, well duh, ozymandias kill Bubastis(his pet lynx) i mean i hate it when movies, comics, tv shows, video games randomly kill off normal animals without reason, like in doomsday when they suddenly shoot a bunny and make it explode, wtf? but anyways, seriously, why did he kill Bubastis, it made no sense to me. answers would be nice, thanks.