Don't forget Chimps ! Gawd I hate the thought of what they do to them.
They already are being used in experimentation, but their organs are either too big or small for humans
pigs and sheep are closer matches it seems.
Are you thinking of the reports of cattle being found with organs surgically removed?
A rancher with whom I spoke said that they had experienced that, and that there was no sign of any blood. Is that usually the case?