Sorry for being so late to the party...
Laura, everything I have seen of you on this site, is you behaving with kindness and compassion. Being with a man that cannot respond with in like is not worth your time.
Asking you... or telling you, to give up something you are passionate about, unacceptable on every level.
Your love of animals, even if he does not "get it" is something that if he was passionate about you, about what makes you who you are, is something he would want to know about, want to embrace, or at least understand.
Many of us have spouses and partners that are not as passionate about our hobbies as we are, but they would not ask us to give them up.
My spouse is an artist, and I love the arts, but do not share the same deep committment, but I would never ask that he modify what inspires him and makes him see the world is a way that allows him to create.
I like snakes, and that is my passion, and it is understood, that although different, our unique ventures makes us stronger individually and so we can prosper as a diad.
We meet halfway, and it is a great place to be.
I know you have heard it and I think you know it, but
this person is not celebrating you. and he should. The perfect person for you is just waiting patiently for you to get off the loser train.
Sometimes you do have to teach a new partner how to relate, that is part of building a relationship, but it is reciprocal. Buddy has an open slot marked GIRLFRIEND and wants to plop you into it perfectly.
Ever hear the expression "round hole - square peg"... you are not the fit for him, and it sucks to be him.
Just a matter of time till he tells you "whatcha talking to those internet snake losers for? You don't have any snakes!"
I hope you can make this decision and do what you need to do with minimal drama. Nothing worse than dreading a decision because you dread the consequences.
My heart goes out to you. Pull on the supports around you and do what you need to do.
Bruce
PS:
A friend of mine... a PhD in Social Psych used to hear that from her partner. One day as she was bending down to pick up her dropped keys, he said that to her "jokingly", she was not in a good mood and she told him to "give it a rest"... he elbowed her in the back of the head so hard that he knocked out 3 of her teeth on the doorknob.