Confirm or disprove my theory as to why one of our hens became too weak to function.

[beesbeesbeeswoo]

Found 25 week old Black Copper Maran pullet unable to walk correctly, kept stumbling over in coop. Acting sluggish as well. This was over a 6 day period until it was culled to prevent suffering.

My primary concern is that the day before this bird began walking poorly, a rooster badly hurt another rooster who is now recovering well. Before that aggressive rooster had been chasing hens too much, he hadn't hurt anyone *until other roo* but I was concerned and planned to cull him. I was wondering if he had also given this hen a head injury but did not see any physical trauma on her.


Timeline:
I put it in a cage with food and water. It was eating some and drinking. Gave it B vitamins for neurological symptoms I noticed alongside the balance issues, as it would repeatedly tilt its head mostly from side to side in an unfocused manner. Pupils and eyes appeared normal.
That evening bloody droppings present, continuing up until it went off feed. Photo below of one of the droppings, many of them contained much more blood. Stopped B vitamins despite neurological symptoms, dosed with CORID for three day period because there was a lot of blood present and I was concerned it was coccidia from stress.
Her condition remained about the same. Neurological symptoms, sluggish, bloody droppings. Remained standing most of the time, would not move around in enclosure.
At the end of CORID dose she passed a very large roundworm, photo below. I was concerned it was a worm issue. I gave it 1 dose Ivermectin, B vitamins next day since I was done giving CORID.
Day before cull it felt colder than a chicken should, concerned feet were not functioning well but it remained standing.
Day of cull could not stand up. Throughout treatment had been syringing egg yolk onto tongue since it had been off feed after first day or two. It had been swallowing the egg yolk, but today would not swallow on its own. Often held its eyes closed, head flopping around weakly. Cold temperature. I believed she was going to die soon and culled her since she was spitting up yolk, not in a good state. My *original* guess was head injury and heavy roundworm load but it was just the singular roundworm. I concluded instead the single roundworm was passed because there were no nutrients, upon inspecting organs and intestine I did not see anything abnormal.

Throughout this I have monitored rest of flock. No similar behavior in anyone else, they are all acting normally. Have inspected poop below roosts every night and found nothing abnormal.

I have not done an necropsy before except to confirm a broken neck, so my methods are probably lacking. Here is anything that looked suspect to me during necropsy below (graphic photos):

Spongy hole-like texture in lungs in first photo?
Then in second photo the right top lung texture looks off compared to left lung.

Massive gallbladder, saw this could occur if bird is off feed but wondering if there are any other causes?

Are bumps with darker dot in the middle on interior of proventriculus normal? They are on upper half of it in this photo.

Interior of gizzard.

No photos of intestines, I expected them to be full of roundworms and they were not. Let me know if the organs look normal.

New theory to confirm with you all:
Head injury from rooster, stress from that leading to coccidia, general inability to eat properly leading to weakness / decline?

 

[dawg53]

In the first photo, there appears to be tapeworm segments in the feces. This could be a cause of the bloody feces, as well as large roundworm(s) as identified in the 2nd photo.
Most likely it's the worms, not coccidiosis that took down your pullet. It would be best to worm your birds with Albendazole or Safeguard liquid goat wormer.
If you see tapeworm segments in feces, use Equimax equine paste to eliminate them.