A person who loves animals more than humans is called a zoophilist.
A zoophilist is someone that loves animals more than humans or loves animals in general so much and is concerned with the animals rights and protection from abuse.
The term zoophilist can also be used to refer to a person who is afflicted with zoophilia which is a sexual attraction to animals.
Some people who love animals so much and love them more than humans can also be called simply an animal person or animal lover.
Some people have the nurturing disposition or protective instincts for animals.
Genetic variations can also play a role in animal sympathy.
And early life encounters can also impact how people also view animals.
Other animal lovers also have early life encounters which can impact how they view animals and some people also have personal beliefs and experiences can lead to a deep connection with animals.
Animals are also often seen by many people as being vulnerable and innocent which can evoke strong emotions.