The "mad cow" disease in deer and elk IS the same exaclty. Guess how they got it? HUNTERS!~ They set up bait feeders to entice deer so , like fish in a barrel, they can be shot later. The feeders were filled with cattle feed. Cattle feed had ground up sheep and cow brain tissue in it. The deer eat it. I know of two packs of hunters who ate these deer and all got mad cow disease. Homeless shelters won't accept it anymore!
I don't know what "absolute animal rights" are either. To me, it seems the "animal welfare" movement aims to put lighter chains on the slaves. I am for veganism, and the abolition of this master/slave relationship between humans and the OTHER animals. We ARE animals, or did God make you in his image, to just USE all your fellow beasts? The eastern concept of "Ahimsa", to do no harm, combined with "The Golden Rule" extended to include ALL earthlings are my ethical guides. It isn't only that we should not hurt other animals, in my opinion, we have no justification for using other animals at all. They are not our possessions, we are not their masters.