Chickens sick, very strange symptoms

[FeatheredFriends&Horses2]

Okay, this is probably going to be the longest post ever, but here we go.
This past summer we had to put down a chicken named Goldie. Her symptoms could basically fit nearly every common chicken disease. We had baby chicks, but not in the coop.
Goldie (roughly 5yr. old hen):
-lethargy
-severe weight loss
-refusal to eat or drink
-gave up on life, if another chicken ran her over she'd just lay there
-no egg-laying
-crop swollen but no foul smell
-would huddle up with tail drooping towards ground
She was the only one who got sick. We had to put down another hen at the same time, but she had a prolapsed vent, so I didn't think it was related.
Then, several months later we had the young pullets in with the older chickens. Now, over the past couple months, we have lost two more birds and have more sick. (We lost a few baby chicks, but they were all unrelated cases, the first ones got too cold, and the last one got suffocated by the others.)
The one to die after Goldie was a three year old hen.
3 yr old hen:
-same symptoms as Goldie
-found her dead one night, one leg behind her, neck stretched out, spot of blood by vent
Then a couple weeks later...
3 yr old Brahma pullet:
-same symptoms as above birds, even died in the exact same spot and same way as the other 3 yr old.
-this time after her death, I inspected her before disposing of her. Her abdomen around her vent was extremely swollen, it looked like someone had yanked her tail and there was frozen blood all around it, and her two hip bones were nearly poking out of her skin.
Now, I have a few more sick, all displaying the same symptoms as Goldie, except at this point they're still eating, however I have a 3yr old rooster acting sick, a 5yr old hen who also keeps kicking one of her legs back, and one of my new pullets dripping mucus out of her mouth.
We also have five ducks, and I was worried that they were causing disease, they live in the same pen, but a different house, and I recently switched from a fountain waterer to a nipple waterer. Sorry for the long post, but I have no idea what is going on. Perhaps they're all separate cases and I just got the bad luck of having them all at once.If you want any more info, ask and I'll see what I can do. I would really appreciate any ideas.

 

[Wyorp Rock]

I'm sorry for your losses.
Photos may be helpful - your flock, coop/setup, poop, anything else you want to share.

Where are you located? (state/country)
It would be a very good idea to have a necropsy performed if you lose another one or if you are up to it, do an informal investigation yourself - look in that abdomen, at the internal organs, etc. Take photos and we will help you with what you see.

The pullet that has mucous dripping out of her beak - can you look inside the beak for any signs of canker, lesions or plaques? How does her crop feel - is it empty in the morning before she eats/drinks? Does she have any discharge from the nostrils, facial swelling or watery/bubbly eyes, coughing, sneezing, etc.?

It sounds like you have a lot going on. Go back to the basics. Fresh food, fresh water.
Check crops to make sure they are emptying in the mornings. Look everyone over for lice/mites and get a fecal float to rule out Coccidiosis and worms. Bringing in new birds from other places can introduce disease and parasites that existing birds may not have resistance to.

I don't know anything about ducks or housing them, so can't really say if they can be kept with chickens or not. If your coop is staying wet, then it may be a good idea to house ducks separately. Look for mold/mildew just to make sure that's not causing a problem.

 

[FeatheredFriends&Horses2]

Thanks! We are in southwest Nebraska. Here's a couple pics of our coop.

We have 20 chickens in all: 13 pullets, 1 cockerel, 5 hens ranging from 3-5 yrs, and 1 rooster that is 3yrs old. I've looked at the pullet with the mucous, and her mouth appears to be fine. The chicken house (the bigger one) is fairly dirty right now, but it has had some good cleanings since the first bird died, the waterers aren't kept in the house, so that's not an issue. I keep their food in those two bins, and sprinkle the scratch on the ground and have started putting the laying pellets in the feeder. I liked spreading it, because I thought that it mimicked their natural behavior, gave them something to do, and made it last longer. I haven't had any eggs in a while, but that could just be due to winter.

 

[rebrascora]

I'm sorry you have suffered so many losses.
Do you have male ducks or are they all females?
If you have one or more drakes, have you seen them trying to mate the hens?
The swollen abdomen could be salpingitis (infection and impaction of the oviduct) caused by drakes mating the hens. Salpingitis can also result in crop problems as the gut becomes constricted by the mass of lash egg building up in the oviduct. The digestive tract gets stopped back to the crop and the bird loses weight because very little food can pass through their system.
Another possibility with the dead birds having one leg back, is perhaps Marek's (although it usually affects younger birds), especially if you have added new birds to the flock. Marek's can lie dormant for weeks, months or even years and then birds suffer an outbreak when they are stressed, perhaps due to moulting or being pursued by a randy drake or confinement due to bad weather.
All the deaths may be related or some may be unrelated. Without a necropsy, it is impossible to tell for sure what killed them but if you have drakes then I would pen the ducks separate from the chickens. Salpingitis can take weeks to come to a head so even if you separate them, there may be others that become sick afterwards.
Older birds are more susceptible to reproductive ailments like Salpingitis even without the presence of drakes and diet can also play a role. It is important that they receive a balanced diet (predominantly a formulated pellet or crumble) and are not given too many treats like scratch or corn or bread.

 

[FeatheredFriends&Horses2]

I'm sorry you have suffered so many losses.
Do you have male ducks or are they all females?
If you have one or more drakes, have you seen them trying to mate the hens?
The swollen abdomen could be salpingitis (infection and impaction of the oviduct) caused by drakes mating the hens. Salpingitis can also result in crop problems as the gut becomes constricted by the mass of lash egg building up in the oviduct. The digestive tract gets stopped back to the crop and the bird loses weight because very little food can pass through their system.
Another possibility with the dead birds having one leg back, is perhaps Marek's (although it usually affects younger birds), especially if you have added new birds to the flock. Marek's can lie dormant for weeks, months or even years and then birds suffer an outbreak when they are stressed, perhaps due to moulting or being pursued by a randy drake or confinement due to bad weather.
All the deaths may be related or some may be unrelated. Without a necropsy, it is impossible to tell for sure what killed them but if you have drakes then I would pen the ducks separate from the chickens. Salpingitis can take weeks to come to a head so even if you separate them, there may be others that become sick afterwards.
Older birds are more susceptible to reproductive ailments like Salpingitis even without the presence of drakes and diet can also play a role. It is important that they receive a balanced diet (predominantly a formulated pellet or crumble) and are not given too many treats like scratch or corn or bread.

Thanks! We have 3 female ducks and 2 males. Whenever I've been out there the ducks just stick to themselves, but it could be. I'll see what we can do.