3 lost from unknown issue-suspecting mareks

[Petals n Pitchforks Farm]

I have a small flock of orpingtons, I lost one hen (around 24 weeks old) 2 months ago, just lost a rooster 2 days ago (similar in age) and a younger cockerel yesterday. This is what they’ve been experiencing:
Starts as diarrhea (no strange colour or blood), after a day or so it turns into bloody, goopy poop and then it firms up and turns a green or is literally liquid with clear/white/green. They eat and drink normal. I have given them herbs, ACV, medicated feed and vitamins in their water.
As soon as I notice issues, I bring them in and isolate them with all of the aids listed above. They’ve lived for 4-6 days and then just rapidly drop weight and pass away. I did end up culling the cockerel because he seemed to decline more rapidly.
The two older had zero physical symptoms, the cockerel did get wobbly and uncoordinated on the last day.
They do not have heat in the coop, it is cleaned regularly (bi weekly), we have had crazy weather fluctuations and it has gotten cold or been damp a lot.
I have another hen that is starting with diarrhea and I’m just trying to figure this out before I lose another one. If I do lose her, I will be taking her for a necropsy. They are expensive in our area and I have to travel 2 hours to get her to the location which is the only reason I haven’t done so yet.

 

[Eggcessive]

Sorry for your loss. What is your general location? If there was bloody droppings, I would think about starting some Corid in their water for 5-7 days in case of coccidiosis. Worming them with Valbazen 1/2 ml orally, and repeating that in 10 days would be helpful. SafeGuard Liquid Goat Wormer 1/4 ml per pound for 5 consecutive days is another choice for worming. Here is a list of most state vets to contact for a necropsy, so call them and ask how to ship or deliver the body if you lose another:
https://www.metzerfarms.com/poultry-labs.html

 

[Petals n Pitchforks Farm]

Sorry for your loss. What is your general location? If there was bloody droppings, I would think about starting some Corid in their water for 5-7 days in case of coccidiosis. Worming them with Valbazen 1/2 ml orally, and repeating that in 10 days would be helpful. SafeGuard Liquid Goat Wormer 1/4 ml per pound for 5 consecutive days is another choice for worming. Here is a list of most state vets to contact for a necropsy, so call them and ask how to ship or deliver the body if you lose another:
https://www.metzerfarms.com/poultry-labs.html

Thank you! I am in Canada actually so things aren’t as easily accessible up here for meds but I was able to get some amprol and started that this morning. I dewormed back in November before all of this started with ivermectin but I will do another round. We are having a damp, cold winter here with fluctuations of milder temps and then gets quite cold.