Hi Joe, Happened to my young birds, green not slimy, birds stopped eating and just went and stared into a corner then died. Went to vet after 5 died, I removed another 6. Post Mortem carried out, nothing found, tested for all viruses, ADENO, CIRC, ROTA. The lot negative, 5 or 6 days after the last one dying, birds back to normal. They were given nothing except a probiotic while awaiting results, which took about 15 days. Was advised by vet to give them something to stop secondary infection which I did, birds were only vaccinated with Colmbovac vaccine after this happened.