Teachers spend half their lives looking for a student with an original thought! Don't just follow the status quo- be the original. You have a topic that is not only original, but it also carries social importance. Let's just say that in 20 years, you'll still care about puppy mills and you won't give a darn about school lunches.
It's a great topic. And don't hate me for saying this, but this teacher who is hard on you is the one you will remember when you are in a successful and meaningful job.