These are old english game bantams, they are show stock. I hatched 14 of 26 last week. 2 died within hrs and the rest were fine until yesterday. Yesterday was horrible - started out with 1 bb red chick on it's side one leg straight out behind it. I removed the screen wire I always put them on and placed clean paper in - he died. Got up this morning and all are dead except 5 and ohe of those keeps getting on his back and I have to turn him over. I put some wet food that I added more vital and duramycin to in for them. Temp is fine. I feed chick starter, give water that is medicated and has Vital vitamins in it. Have hatched several times this year and no losses. Please help as I have no clue what this is. All my eggs come from my own birds - no ordered eggs, no new birds, etc. Thank you