I had chickens, geese and ducks as a child but this is my first time having chickens as an adult. Two weeks ago we got 6 pullets - Barred Rock, White Rock, Speckled Sussex , Buff Orpington, Black Star and Red Star. All 6 weeks old except the Speckled Sussex who was just 2 weeks. We got them at the chicken swap. The Sussex died a week ago and then the Red Star. The White Rock died today. All were eating and drinking and playing with the others when they started sneezing and then they began to slow down. Orange watery poop, then they died. They're in a coop with a heat lamp. Sawdust/wood chips on the floor and they're eating Start and Grow. Any thoughts or ideas are desired. A couple days after we got the first batch we got 3 more. One is a 12 week old Maran and the other 2 are 4 week old Easter Eggers. Those we got from a breeder. I should have waited and made sure the swap pullets were healthy before adding more, I see that now. I 'm concerned about the rest of my flock. Antibiotics? Different food? I'm willing to try most anything. Thank you!
Possibly coccidiosis? Are they being fed a medicated feed to prevent coccidiosis? If they already have an infection, they will need treatment which will involve giving them coccidiostats beyond that in the feed. Here is a web page with some great pictures of chicken droppings: http://www.the-chicken-chick.com/2012/02/whats-scoop-on-chicken-poop-digestive.html
You may have a couple of things going on and I agree that I'd treat for coccidiosis with a course of Corid. It's a very high possibility since you've got birds from different places now sharing space. The sneezing is a concern but chickens do sneeze in reaction to dust and other irritants just like we do. Look for runny noses, bubbly eyes, coughing. Some diseases also cause swelling around the eyes. If you see further symptoms you'll need to decide if you want to start treating them. You can usually save them and clear up the symptoms but many respiratory diseases can be an ongoing, recurring thing that you always have to deal wiht and they can keep infecting any new birds you get. Another good reason not to buy birds from a swap. To many birds and unknown backgrounds.
CAFarmGirl is correct. If they have mycoplasma or CRD, treatment can suppress the disease, but it can, and often does recur. And yes, they can infect any new birds. The usual recommendation is that birds with CRD or mycoplasma be culled. Which is grim if you are attached to them; but it saves additional suffering by other birds.
If you loose another bird and it becomes obvious that a respiratory issue is going on see about getting a necropsy done, preferably by a state lab. Some states do them for free, some charge a fee. It would be very helpful to you to know what you are dealing with as well as how best to treat or manage it. Edited to add: If you have access to an avian vet you can also have a live bird tested. But start with the Corid and go from there, hopefully the sneezing is just environmental.
This is all so very helpful, thank you everyone. All the birds seem fine but maybe it's best to go with a course of Cordid.
Thank you all for the help! I gave the pullets a round of antibiotics and they're doing great. They've grown like the Hulk!