We've lost 3 birds over the past several months.... All three different breeds, one guinea, one speckled Sussex, and a lakenvelder. All of them were about 2 1/2 years old and died one at a time with 3-4 weeks between each death. They seemed extremely lethargic and showed signs of having diarrhea, but the symptoms were only present for a couple hours before they died. We asked for some advice at the feed store after the second death... They thought maybe dehydration leading to them being egg bound. We provided electrolyte enhanced water along with their regular waterer. We also completely cleaned the coop as well as all waterers and feeders. The third died tonight..... Any thoughts on what else may be causing this???