Sorry for your losses.
I'm not a vet, but I work in human medicine. I agree with the respiratory aspect being infectious and passed from hen to hen. Mycoplasma is hard to culture in humans, too. That may have started the illness. She may have gotten weak after that, fed/absorbed poorly and laid internally. Weakened conditions cannot effectively fight off additional stress.
As far as the source, I agree with the outside birds carrying the disease. You'll need to move the food. My feeders are in the secure run, behind chainlink, and in the coop. Now you've got me watching!
Although rare, chicken to human infection can occur, especially if you are immersed in it. Wash hands/arms/face, change clothes when done. Your vet will have more ways you can protect yourself and your girls.
I'm not a vet, but I work in human medicine. I agree with the respiratory aspect being infectious and passed from hen to hen. Mycoplasma is hard to culture in humans, too. That may have started the illness. She may have gotten weak after that, fed/absorbed poorly and laid internally. Weakened conditions cannot effectively fight off additional stress.
As far as the source, I agree with the outside birds carrying the disease. You'll need to move the food. My feeders are in the secure run, behind chainlink, and in the coop. Now you've got me watching!
Although rare, chicken to human infection can occur, especially if you are immersed in it. Wash hands/arms/face, change clothes when done. Your vet will have more ways you can protect yourself and your girls.