I agree, that you should have dead birds necropsied. It should be done asap after death for the best results. Here, the California Animal Health and Food Safety Lab will do poultry for free. Ask at the local university or vet to find the equivalent in your state. It's especially important since you have had multiple birds die in a short time.
I'm sorry that you've had so many chickens die. It sounds like you are doing everything that you can for a healthy flock.
I didn't have that experience with my SH chickens. One of their Dorkings didn't hold up to the extreme heat that we have here in summer, but that was my only loss of birds from them.
I haven't had the sudden death issues of healthy Dorkings that some of you have described. Every year or so, I might have one chicken die, with no reason. At one point, I was feeding too much grain, which caused fatty liver in my flock. That's the only possibility-although improbable-that I can think of for your birds. Layena is mostly corn based, but plenty of people feed it without problem.
I wish that I could be more help.
Kim
I'm sorry that you've had so many chickens die. It sounds like you are doing everything that you can for a healthy flock.
I didn't have that experience with my SH chickens. One of their Dorkings didn't hold up to the extreme heat that we have here in summer, but that was my only loss of birds from them.
I haven't had the sudden death issues of healthy Dorkings that some of you have described. Every year or so, I might have one chicken die, with no reason. At one point, I was feeding too much grain, which caused fatty liver in my flock. That's the only possibility-although improbable-that I can think of for your birds. Layena is mostly corn based, but plenty of people feed it without problem.
I wish that I could be more help.

Kim