Utterly facinating - great post, thanks for posting.
Chuck reminded me of 'Joanna' a Sussex purchased recently at the market by a chum for a neighbour. Joanna was gorgeous, wonderful plumage and sweet as could be - loved a cuddle. She was joining two other chucks, one another Sussex and t'other a red - small and fiery red who took it upon herself to set about poor Joanna. Next thing was, that Joanna was seen to have, like, stiff legs and ***hips!! Her back legs were splaying out at the back and she struggled to walk (suspiciously like AS?) I found her several times in a desp state and wanted to bring her to the vet, or...do the 'kind' deed. But, not my chuck!
She was wormed, and after that began to slightly pick up. She began to eat better, and generally perked up. But, was still 'stiff' in her hips and legs. Just as she was beginning to stand up to the vile red monster, a fox got into the coop, took out the two Sussex chucks and ran off *with the red monster - no doubt made a bit of a stringy meal. Strange the fox did not favour the plumper Sussex gals. Oh well

We are all very sad at the demise of Joanna - would have been *very interesting to see how the legs/hips panned out. But she was certainly moving better, almost normal in fact, though still perceptively stiff in hips/legs. A spondy chuck? Hmmmm...

Joanna was about 21 days old, point of lay at purchase, and the fox killed her when she was about 7 weeks old, so that would be 49 days...ties in with the article! The other Sussex was some five yrs old, in fine fettle and laying every day - yes, Joanna also did lay, this in spite of her disabilities. Good gal.