I say all lines are figments. We do so much to try and seperate ourselves from the rest of the animal kingdom. But really, what seperates us, or cats, or dogs, or snakes from any other carbon based life form on this planet? Mostly our egos imo. We all fit nicely into the food chain.
I say if it will help control overpopulation, do it. This planet is completely overpopulated now.
Plus i find it hard to get all pissy about F/T kittens when it is perfectly ok to snatch wild critters out of nature and put them in glass boxes for the rest of their lives like tiny scaley felons.
Just my two cents