Pattern A is the familiar surgical sampler: eye, tongue, anus/rectum, reproductive tissue. And those choices are considerably less random than they sound. Retina is basically exposed CNS. Rectoanal mucosa is lymphoid surveillance tissue. Oral tissue gives you another host/environment interface. Gonads give you endocrine state, reproductive history and germline material.

If your problem is “what is happening biologically to this herd, across geography and time?” that is a very efficient panel. Neurologic, immune, alimentary, reproductive.

Then there is Pattern B, which is much stranger: essentially the animal gets reduced. Blood gone, viscera gone, huge amounts of skeletal muscle gone. In one Kelleher case the eye was excised intact and left sitting beside the carcass. Discuss.

(http://www.autoadmit.com/thread.php?thread_id=5901471&forum_id=2Reputation#50121660)