I would say it was those birds lucky day when parents divorced,you will start to notice a difference in your chickens after they have been properly cared for,good thing these birds have you and your partner to look after them.I have the stuff ordered and it's on fast delivery should arrive on or before the 3rd of March, they have never been wormed so it it a possibility that worms are a cause? ( they are my partners dads, after a divorce both of his parents refused to care for them so me and my partner took on the responsibility ) there are rats under the shed that they sleep in and the conditions were filthy were the poo was never scrapped up, could the rats have something to do with it, we have poison and traps down
Yes,filthy conditions with poop everywhere can cause among other things respiratory issues from buildup of ammonia,can cause burns to feet from ammonia and harbour parasites. Rats carry parasites which spread to birds.
Definitely get rid of rats,just make sure chickens have no access to poison. I would suggest worming your chickens also.