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.
The major in undergraduate is mostly irrelevant - the important goal is to make sure you have completed all the pre-requisite courses for applying to vet school. However, most vet school applicants major in biology, chemistry, animal science or a related field since these majors are pretty close to the list of pre-requisite classes for vet school.
I would recommend taking Computer Science and Math at a high-school level.
LSU, good school
There are pre-veterinary medicine majors out there (I actually graduated with a BS in pre-veterinary medicine), but they aren't as useful as a straight science major. Most applicants to vet school have a BS in chemistry, biology, zoology, etc. - one of the core hard sciences. There are also a number of applicants with bachelor's degrees in agriculture, animal science, etc.
It depends on the level. If at the two year level it would be an associate of science degree (AS). If at the four year level it would be a bachelor in science degree (BS). If at the master's level it would be a master in science (MS).
No. yes you should even an artist or writer must know some science, People that do not take science classes i personally classify them as educated idiots excuse the language.
You'll need to major in Marine Biology, unsure about number of years you need.
There are no certain high school classes that are required to become a criminalist. Any advanced science classes whoever would be beneficial. A criminalists is required to complete a bachelor's degree program with a major in chemistry or a related physical or natural science.
Students have to take 1 science course at Emerson if they didn't take an AP Science in high school, and most students don't have to take math if they did decently well in high school math or on the math section of the SAT. WLP majors can take photography, theater, dance, and music classes to fill their some of their GenEd Courses, or in open spots in their schedules.
Animal science career will include but not limited to, breeder, horse trainer, and livestock production. http://www.mymajors.com/animal-science-major#positions
UC Davis offers an Animal Science major
It depends do you have polymer science?