To make a Plektos, you have to have not only a boatload of blood but a profound and detailed understanding of the teloi that you’re trying to change. Not just any Theurge can create viable, living Plektoi; it takes biological specialists, veterinary surgeons, inheritors of a long tradition of failed experimentation who learn their craft from master Plektasts.
The difficulty in spending enough time tweaking wild animals and (even more so) doing the necessary breeding experiments to gain your insights is the reason Plektosis is only really done with tamed animals (with a bit of superficial wild boar telos threaded back into the Halassurq war-pigs at the end to increase aggression).
Working with truly wild animals is more of an Abhuman thing, and the way they get their insights is considered an abomination by the Hegemony. 