How can I deter my son from wishing to get into animal husbandry?

I'm pretty ashamed of this to be quite honest. Please don't look down upon me for what I'm about to say. I love my son very much and support him in his college dreams and goals in life. He's a very smart boy and has done well in high school so far. I'm very open to gay rights and have even told him I'm supportive of him whether he dates girls or guys. I try to be a hip mom. I thought nothing much of the fact that he hasn't dated anyone yet. I figured he was just too busy with school or sports for girls. Boy, was I wrong! This is really difficult for me to say but he's very open and enthusiastic about his desires to get into animal husbandry once he goes off to college in the fall. I'm very much against this idea, as animals tend to carry disease and , in my opinion is quite wrong. Should I continue to support him in his dreams? How should I approach this touchy issue?