Most likely they would be disease free but the penalties of being wrong could force you to start over. Call your State Fisheries people. They can tell you who to contact. Ask the State guys what their stocking recommendations are for your personal situation. The Pond Boss pro's recommend about 800 bluegill or coppernose and 200 shellcrackers or those approximate combinations along with about 5 lbs. of fathead minnows per acre. Leave them alone for a year and come back with 50 bass. A lot of State Biologists say you can start out stocking with half that many bluegills, etc. Who's right? Who knows? Before I stocked any forage fish, I would check my PH and alkilinity to find out whether I needed lime. Build a sechi disk to look at your water clarity which is an indicator of phytoplankton (or maybe mud) availability. All of this is discussed in Bob Lusk's book "Raising Trophy Bass". I'd buy it. You can get a lot of info by going over the posts here. Have fun. It's just money.