Someone who loves animals is usually just referred to as an animal lover. However, since you placed this question under mental health, I will also include that someone who has sexual relations with an animal commits beastiality, which is a crime.
A person that assists in handling animals can be called a groom if they work with horses. A person who works with zoo animals might be called a trainer, zookeeper, or handler. A person who raises animals for food might be called a rancher or dairy farmer.
A person who loves cats is typically referred to as a "cat lover" or a "cat enthusiast".
zookeeper
She= elle Love= amie Animals= animeaux In a phrase, you would say, "Elle aime les animeaux," meaning "She loves animals." \
Zoologists study animals and botanists study plants. Biologists study both plants and animals together. Microbiologists study these things at a cellular level.
A person that loves animals has a lot of love in their heart. Animals give unconditional love and just want it in return.
An animal lover. There's no specific vocabulary for a person who loves animals. ^-^
A person that loves books is called a bibliophile.
A person who loves to sleep or a person who has an obsession with bed rest is called a "CLINOMANIAC."
Such a person could be called an acrophile.
pedophile
A person who studies animals is called a zoologist.
A person who loves their country is often referred to as a patriot.
A person who loves outdoor activities could be called outdoorsy. This means the person loves to be outside and involved in nature.
vain vain
Bibliophile
A bibliophile is a person who loves to read.