Google IBR (income based repayment) and PAYE (pay as you earn) to get info. Essentially you pay 10% of your discretionary income per month each year for 20 years, and the remaining balance is forgiven but the forgiven amount is taxed that year as income. It has to all be federal student loans (no private loans) and there are some other criteria. Just look those up.
If you want to know what your payments will be per month and how much you will pay back over your lifetime, and if you pay with IBR/PAYE how much the tax might be at the end (that one's a little sketchy because income tax varies year to year... And remember you also have state income tax in most states on top of federal), here's a calculator to figure that out for you.
http://www.vinfoundation.org/AppUti...357&objecttypeid=10&redirectFromMiscDefault=1
If you want to know the cost of attendance of different vet schools, use this site (just remember that with tuition hikes it
gets worse each year):
http://www.vinfoundation.org/apputil/project/defaultadv1.aspx?id=5327182&said=-1
There's also a ton of discussion on SDN about it both in veterinary and medical forums, so just do a search with IBR and PAYE. Rules have changed so look for threads 2014 and younger.
Biggest pain in the ass about the programs is that you have to qualify each year (and as a veterinarian, you will... Trust me on that one). With the bureaucratic idiocy that comes with federal govt programs, that's hard to do without a hitch for 20 years. If you don't recertify on time, you are kicked off the plan and any unpaid interest at that time will capitalize onto your principal.