I'm sorry to hear about your situation with your mother. Just try to focus on what you want and what path you want to go down. It's easier said than done but don't listen to your mother. If working with animals makes you happy and it's something you want to do, then absolutely go for it =) I also want to with animals/dogs
There's always a chance that you will have a person in your life that will criticize you. But just ignore them. Be what you want to be.