What do I need to take in college to become a Dr. of Zoology?

Not really clear on exactly WHAT you want to do at a zoo..if you just want to be a keeper, you don't need a Phd..but will likely need a Bachelor of Science degree (4 year program). If you want to be a zoo vet, you will need to earn a B.S. then attend vet school for a minimum of an additional 4 years. If you want to be a curator, you will need an advanced degree as well. Many curators start out as keepers and after MANY years work their way up to curator. Not really sure what you think a "doctor of zoology does"...if you have the title of "doctor" it just means you hold a Phd, but it does not necessarily represent a job title! Also, jobs in this field are highly competative, hands on experience counts just as much as a degree.