Hi, all, I have a mixed age backyard layer flock and I’m based in Oregon. We just had two out-of-season heat waves — 3+ days in a row of over 100F followed by some very temperate to cool days and nights (70/50F) — about a month apart and I noticed drops in egg production the first round (went back up after 4 weeks) and now after the second round I had one hen pass and another is pretty sick. Flock is vaccinated for Mareks after it got on the property from an unscrupulous Craigslist seller the first season I had birds and I’m pretty sure that a pair of birds that got dumped at a local park brought something else - MG - and some other hens I bought earlier this spring to fill increasing egg orders from another guy probably brought something else (diarrhea, light green poop). The thing is the flock is otherwise pretty healthy. I would say chronically slightly under-laying, but healthy and active and productive. Sometimes get leg mites and I treat with elector psp, dust with poultry dust if they get lice or feather mites, etc. They get fresh vegetables, are fed an organic local pellet, oyster shells, black soldier fly larvae, greens from the garden, etc. VermX herbal pellets for gut health. Treating with Corid seemed to control the diarrhea until this last heat wave. Now one hen died last night (I processed her but the liver had small white spots on it so now everything is in the freezer til I figure out disposal and I disinfected all the surfaces with alcohol) — had extra water in her belly, and probably sour crop (it smelled bad when she was throwing up water as she died). Otherwise still a beautiful healthy bird. Another has been sick (lethargic) with a swollen eye for about 4-5 d and today it’s closed. She had 3 d of Tylan 50 injectable, wasn’t getting better, so I stopped yesterday, but she got worse today . Now I put Tylan 100 powder in the water for everyone with the hope of preventing another full flock outbreak. Has anyone experienced anything similar with a flock that probably has had multiple infections but recovered, only to see the next stressor knock em over the edge? Any tips or thoughts? I’ve had ACV in the water and that helped too, early on. I’m so sad and I’ve spent so much money on chickens, gear, coop, run, meds, maintenance, treats ... I just want them to be healthy. Honestly one of them lays an egg once every 2-3 months, I’ve nursed them back from lots of stuff, some are hatched on site and others were bought as chicks or adopted as hens ... but it’s so nice to have a flock. Depending on how this develops I’ll probably have to make a decision to let these guys age out and then sterilize the property. Does Virkon work on soil? That might be a solution to get rid of microbes at this point. One last detail, it does seem to be the 8month to one year olds who are the most rough looking (feathers in rough shape).