How could Hitler protect animals and limit by law animal experimentation while permitting cruel medical experiments on humans in concentration camps?

This is probably one of the best examples of Hitler's
political and personal cruelty.  In order to consolidate his own power and eliminate
opposition to him, Hitler's design was to deem the enemies of Germany as less than
human.  This dehumanization was what allowed the ease with which so many were tormented
and killed.  It was not that Hitler ever said that "These are bad people."  Rather, he
made the argument that individuals who were against him only did so because they were
actually less than human.  Throughout his writings and speeches, the targeting of
individuals of Jewish faith or homosexuals or gypsies was done so as arguing that the
true standard of being a human being was not met by these groups of people, so keeping
them is a crime against humanity.  This sad and twisted logic was embraced by so many. 
Once the floodgates had opened in robbing people of their humanity though insult,
dehumanizing comments and terms, and targeting a group of people, the abuse,
intimidation, and elimination was easier to accomplish.