Second Death in Flock of Similar Style

Hi all,

Today we buried my 9-month old black australorp Sidney. Early last week she had seemed lethargic- usually the boss chicken, she was not showing her usual leadership capabilities. I was gone for work during the week, and was woken on Saturday by the fiance saying she looked very ill. She was even skinnier than earlier in the week, and was breathing heavily. She was still alert, but was taking every opportunity to rest.

We brought her inside, gave her mashed up food (corn, mealworms, whatever she'd eat) along with electrolyte spiked water. I even got some de-wormer and added a drop to her water just in case it was worms. Her poop was very watery and was very dark green/black. I don't have a microscope so didn't do a fecal float (I work in the animal industry so I more or less know what to look for) and there were no worms in her stool (at least not to the naked eye). We woke up this morning to find her not breathing and her eyes closed in the basket we tucked her into the night before. She's pooping on god's shoulder now.

I'm sad, but think we did all that we could have given the circumstances. But here's the kicker- about 5 months ago, when we were new chicken parents, my Wellsummer, Madison, met a similar fate. It was mid- summer and she was bigger than the other chickens. She was pooping white liquid, stopped eating or drinking, and was separating herself from the flock, sitting down and breathing heavily. None of the other birds at the time showed any symptoms.

Is there something wrong with my flock, or a latent infection of some sort? These deaths happened a half year apart so I don't suspect a virus or even a heavy parasite infection, otherwise all the girls would show signs. My three remaining birds are clucking along without a care in the world.

I've added de-wormer and electrolytes to their water just in case.

What sayeth the chicken community? Do I have a cursed coop? Also, since I'm down two birds, I was thinking of getting two more peepers to grow and introduce come Spring.

Say a little prayer for Sids- she's laying golden eggs in heaven.