Hi there new as a member and to posting but, I spend a LOT of time reading here about chickens! Ok.. the bad news is today I had to cull my oldest hen, Birdie. She was about 10 years old and an ex-battery hen.. one of these lohmann browns. I culled her because she has been really pitiful looking since about the last two weeks of March. She started presenting with raspy breathing and the neck stretching (I think its called 'pump handle respiration') but, she was eating and drinking, laying and foraging pretty normally. Except she would often spend time looking downright miserable if weather was poor with tail down and not keeping up with the rest of the flock. They free range. Yet, other times she kept up fine and behaved normally. The breathing got worse to where she started to gasp and every now and again make a very loud gasp that sounded like a rooster about to crow. She did a lot of head shaking and sneezing. I dosed them all with Flubenvet pellets for a week. Nothing seemed to change so I then went to the vet and got Ivermectin and dosed her with that. Then antibiotics and nothing. Still the same. Her comb became quite a permanently dark purple but, she had no eye discharge, no mouth discharge etc. and definitely not egg bound. After 6 weeks roughly of her being ill, today I noticed a younger hen doing the pump handle respiration. But that hen looks in great condition otherwise and this is the first time I noticed it. I decided it was time I culled the sick hen as now I feared she was suffering for too long now and also worried it was contagious. My question is... if one bird comes down with ILT... how fast does it move through a flock? I read in one place that it takes 6-12 days to see symptoms when it takes hold in a flock but, this is 6 weeks! Could it be ILT? I'm just feared I will have to cull this next one now as well and maybe the whole lot if its ILT. Vet is young and not so au fait wi poultry I believe. I never thought to isolate as it did not seem to be contagious. Yet now 6 weeks later I have another doing the pump handle breathing only very occasionally. She is not constantly doing it. I have 4 broody hens who all have been isolated for about 2-4 weeks all in separate broody coops. I have decided since these 4 have been isolated that I would quarantine the main flock (only 5) in their large run instead of letting them free range until I can figure out what is going on here. I still have the hen I culled. Should I necropsy myself and what should I look for to rule in or out on ILT? Anybody have any other suggestions or treatment I could try if it is something else other than ILT? And if not ILT.. what do you think? Thanks! Any advice appreciated.