I was in the military and went to night school the entire time. I also went summers and took over 21 hours per semester when I did start full time. After active duty, the G.I. bill paid for college and I took as much as I could stand and keep a high G.P.A. I also took proficiency exams that further extended the number of collective college hours. The actual time from my discharge till I received my D.V.M. was six years but I have over 490 college hours. A normal year matriculation is 36 semester hours; 490 divided by 36 is 13.61 rounded off is 14. Roughly, I have fourteen years of college by normal standards. I took a significant number of Zoology, Microbiology, and animal science courses offered by the university. Most veterinarians can go through seven or eight years of college and get through the curriculum, but at the University I attended, many had other degrees before applying and being accepted to the veterinary college. Some veterinary colleges are receive students with two years of preparation before entering the curriculum which IMHO and many others believe to be inadequate.
Many veterinarians have advanced degrees along with their D.V.M.