I'm a non-trad on my way to applying for vet school. I got a BA in Economics in 2001 and spent the last 7 years in finance, only to realize that there is more to life than sitting in front of the computer for 10 hours a day, interacting as little with the outside world as possible. (Strangely, that is what I'm still doing now as a student it seems like
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Anyway, I left my job last may and have been fulfilling my prereqs at a local community college. The advisers that I've been in touch with were very encouraging about non-trad students, especially from non-science fields. The information I have gathered is that if you can perform at the top level in your science coursework, the non-vet job experience can really set you apart from the rest of the field. In addition, I was pleasantly surprised to find that taking the physics and chem requirements at the community college level was no problem at all. I am taking my biochem and genetics at a state school this summer, as 300+ level classes aren't offered at jr. colleges. I'll be applying to UofIllinois, Auburn, KSU, and OK this summer.. if I get accepted on this 1st round I will be 31 when I start vet school. Fingers crossed.
I am also considering PA school as a backup plan if things don't work out with vet school after a few rounds. But it's not like it's a seamless transition to go from one to the other, there will still be down-time as far as earning the needed experience for PA programs.. Most of the schools I've researched require a minimum of 400 to 1000 hours of actual direct patient care experience, and the positions that you can fulfill that with are: EMT, paramedic, nurse's aide, clinic assistant, etc. Thing is - all of these jobs require certifications if not actual degees, as well.
The other things to consider if you're weighing being a vet vs. a PA would be the hours and benefits.. as a PA you are generally working in a clean, safe, 8-5'ish job, M-F.. I live in a really small town and PA's here easily make 6-figures, full health benefits, retirement, etc. As a vet you are looking at longer hours, some weekends, less pay, and the work environment may not be so cushy most of the time. If you open your own practice, the money may get significantly better, but the time and responsibilities are certainly much much greater, too. I know in my heart that ideally, I would be a vet because I want to work directly with animals. However, if I become a PA I would probably have the time and money to devote to volunteering, donations, fostering, or owning several pets. So I suppose you can't really go wrong either way, but you have to go with your gut and what fate hands you.
Sorry to be long-winded, I wanted to address the PA part of your question.
Good luck!