Bullying, feather loss and spontaneous death

[StuckOnTheFarm]

Hello fellow chicken keepers,
My hubby and I have had several flocks of chickens over the last 14-15 years. The last 2-3 years have been very difficult though as our girls seem to be dying for no clear reason. Our last flock started with about 36 hens if I recall and we ended up with about 22, 2.5 years later and this time we started with 40 and are down to 32 just 6 months later! I do believe 2 from this batch became egg bound and we were unable to help them, but the others I do not have an explanation for. This latest batch started in a beautiful BIG new coop with a large outdoor area, new nesting boxes and everything. One thing I notice is that they are really thin on feathers towards the back end and I have even seen on hen trying to mount and subdue another. We do not have a rooster. Is it possible that they a bullying each other to death? No signs of mites, worms, or any other pestilence or disease. They are ISA browns I believe. Otherwise they are productive layers, energetic, good eaters, etc. Can you help us solve this mystery?

 

[azygous]

I have a couple of questions. At what age did most of the mortality occur among those that you lost?

What were some of the symptoms you observed prior to death?

When chickens appear to die off for no apparent reason, it's very often from an avian virus that may be present in the soil and litter in your runs and coops. Some, such as Marek's is extremely long lived in the environment, waiting in the soil for weeks, months, even years to infect new chickens.

 

[StuckOnTheFarm]

Death has not occurred at a consistent age. It could be anywhere from about 20 week, to almost 3 years old. We've had times where 2 have dies the same week and then all is good for the next several weeks/months. Totally unpredictable. We buy them as layers (approx 16-18 weeks old already) We have tried 2 different hatcheries, and this latest batch has been in a brand new coop about 100 feet away from the last one. The only difference we have made is having a bigger flock (no rooster, and yes plenty of sq ft per bird). As far as symptoms, one I did notice kinda isolated herself on the roost when the others were on the ground, but she seemed fine otherwise, and as I mentioned above lots of feather loss on their backs and around their bums.

 

[azygous]

Since you haven't noticed any significant symptoms that most of the dead chickens shared or any particular age at which they seem to sicken and die, about the only avenue left to you to discover a cause is to refrigerate the next chicken to die and have a lab do a necropsy on the body.

 

[chickens really]

Have you checked them for mites or lice?

 

[chickengeorgeto]

Death has not occurred at a consistent age. It could be anywhere from about 20 week, to almost 3 years old.... … As far as symptoms, one I did notice kinda isolated herself on the roost when the others were on the ground, but she seemed fine otherwise, and as I mentioned above lots of feather loss on their backs and around their bums.

… This latest batch started in a beautiful BIG new coop with a large outdoor area... one thing I notice is that they are really thin on feathers towards the back end and I have even seen on hen trying to mount and subdue another. We do not have a rooster...

Well there goes the old notion that naked backed hens are victims of their rooster.
Almost every feather challenged hen that I have ever seen was suffering from de-pluming mites. Now would be a great time to dip your remaining hens in a tank mix of Permethrin and stand back and watch the new feathers come in. It would have been nice however if you had included your general location so that we would have a general Idea of the current weather or temperature at your homestead.