if it was canker it is contagious but I wouldn't treat the others unless they show signs of it. treatment might be hard on their little systems. but if they show any signs then I'd treat immediately. clean and disinfect there water bowl and food container. I'm so sorry for your loss
white or yellow sores in the mouth of chicks could be Canker. This is a protozoa that effects birds. birds can be treated with Flagyl or spartrix to cure. Symptoms of Canker include yellow or white sores in the mouth loss of appetite weakness frequent swallowing watery eyes. could have a foul...