Those are both good points. The physical changes can be surgical, or more probably computer aided micro-surgery - I mean if the animal has a tail it needs to be connected to the nervous system and form an extension to the base of the spine so it can be wagged and have feeling. After surgery the victim goes into the biochamber to be healed quickly (a few hours).<br/><br/>But bolting ears and tails onto victims doesn't make them act like animals, it just pisses them off, so the other stages of transformation will need drugs, hypnosis, training (Pavlovian, etc), punishments, all that stuff of which the drugs are just part though they help a lot in dulling the higher brain functions and killing off the aggressive tendency making the victim more docile. Throw in hormonal treatments and pheromones and lots of sexual rewards for good behaviour and I think we're well on our way.<br/><br/>So there's the physical (drugs, surgery plus healing process) plus mental degradation/training in two distinct areas.