Did JoJo ever exhibit signs of paralysis, as you'd expect with classic presentation of Mareks? Just wondering as 16 weeks of age onwards is when Lymphoid Leukosis tends to affect birds.
Fascinating that he was an hermaphrodite. A special bird in more ways than one!
I often wonder about Penelope. She has definite male traits (that cocky comb and quite long pointy, hackle feathers) and often disciplines the other hens in the same way as a roo would. She has been known to mate with them (I don't read too much into that as I know it can be a dominance thing). She also crows exactly like Ferdy, a proper crow not just a crow-like bellow as Gladys does. She's always been a bit odd and I was convinced for a few weeks after she hatched she could be a slow developing roo.
Nohope looks so handsome and content. You wouldn't think he had much wrong with him at all! From what you describe he's obviously got some nerve issue - idiopathic polyneuritis??? - but certainly not classic Mareks symptoms. Could he possibly have some sort of brain injury? Or even something like vertigo? Sounds daft, I know. Does the poultry cell have riboflavin, vit E and selenium in it?
There's no possibility of heavy metal toxicity, is there? No lead shot lying around, contaminated water etc? Sure you've already considered all this but it could be that you're dealing with Mareks in the flock and something else with Nohope? Having said that, Mareks isn't always fatal but not usually after the bird suffers paresis. The viscera and nerve sheaths are too compromised by then.
I didn't know a purple comb could be indicative of tumour formation! That's really interesting. I always thought it was low blood oxygenation, poor circulation or even cold air temperatures.
