It sounds as though you have already identified your passion! I would suggest working at an animal shelter or working at a veterinarian office to gain some hands on experience working with animals.
I ended up with a career in finance, but I was a chemistry major in college, not finance or business. I found finance fit my problem solving abilities and my interpersonal skills. It was rather lucky for me to wind up in finance, but since you have already found your passion pursue it with gusto!