How comes if a dog or cat so much as even bites you then you have the right to have it killed yet if one murders another they are only arrested?How comes Christians hate circumcision and human euthanasia yet they have their pets castrated and euthanized?
As far as I know, Christians do not believe that animals have souls, so they don't feel any need to treat them like human beings, who have souls. Also, in Genesis, God tells Adam to look after animals: it seems a lot of people think that means to treat them as we see fit rather than how we treat each other.