Only know about the small animal side, but it is a dead end career. Low pay, not particularly great treatment and no possibility for advancement. If he is fine with that, go for it. It can be fun and rewarding (not financially). It is an industry fairly female dominated. That can be good or bad, just like anything else. The small animal side was a lot of pandering to crazy old white women. That is not easy for a lot of men. There is not usually enough money in a vet clinic for anybody other than the doctors to make any money. The staff get paid, but not enough to raise a family on as a sole provider. I would not recommend spending money on any type of certification. You will probably never get to the break even point on that investment. Another sticking point for some is that when a grown man shows up in a veterinary situation, everyone seems to assume he is the vet. Seems innocuous, but imagine telling every person you meet in your day that you are not as important as they think you are and you are just the helper. It can wear on a man's confidence and self worth. Not all men, but just something to consider.

In short, don't do it. Go sell nails at Lowes or drive the school bus.