You can take the ACT regardless of which classes you take. You can even take it before entering high school.
Classes that veterinarians take in high school would be biology (other sciences) and math
Dance Classes
To get college credit in high school.
It doesn't really matter what classes you take in high school or even in college. The grades you get are more important.
you have to take cooking classes
Your High School classes only have a value in gaining you admission to a college.
Drama
English
Every high school is different. I don't know if there are any specific classes that you need to take. Not all high school's offer courses for animal science.
All the baby classes!
Yes they certainly can. They have an online website where teens can take highschool classes and complete it for their high school diploma. www.k12.com