Help! 2 chickens in 6 months have died, looks like a 3rd on her way :(

[SFChickens]

We had a flock of 5, which we have had for several years living happily together - one buff, three Amerucanas and one golden sex. 6 months ago, we woke up to find one of the chickens near death. The vet had no real explanation without expensive testing, but said the girl was very dehydrated. Fast forward two months and we notice a second chicken not walking around. She was being pecked at the neck and butt, to the point of bleeding heavily. We also took her into the vet, did some expensive testing (all of which came back negative), but she was so wasted away that the vet recommended we put her down. Another few months have gone by and today I noticed one of the hens picking at the neck of another. On close inspection, the poor girl has several deep peck marks in the back of her neck. We will take her to the vet tomorrow but we would really love your help if any of you have encountered anything similar or have any ideas.

Do we just have a bully on our hands that is literally pecking her sisters to death?

Or are there any diseases/issued that would take them one by one in such a slow, several month fashion?

Any ideas would be greatly appreciated.

 

[coach723]

The best way to know for sure what is going on is to have the next one you lose necropsied. A link below with necropsy resources. Your vet may be able to arrange a necropsy for you. The possibilities are numerous. They could all be unrelated and be reproductive problems like infections or cancers, which are not uncommon in laying hens, particularly over the age of two. It could be a virus, of which there are many, that is affecting the flock. It could be bacterial or fungal. If you lose another I would refrigerate the body (don't freeze) and have a necropsy done so that you can try to pinpoint what the issue is. That way you will have information on whether it's contagious or not, treatment or prevention options, if there are any. When a bird dies rather suddenly, with no signs ahead of something going on, then necropsy is often the only way to know. Symptoms can sometimes be very subtle, and go unnoticed, but the other birds often know and will pick on or attack the sick one. It's survival instinct in them to drive the weak away since a weak member can attract predators.
https://www.aphis.usda.gov/animal_health/nahln/downloads/all_nahln_lab_list.pdf

 

[RainbowHen]

What is the size of your coop/run? What do you feed them?