It might be infectious bronchitis... It can damage the unterus of the hens and that causes changes in the eggs shape... However in our flock of many many birds, only a few showed any symptoms, one had symptoms for longer and her uterus got so danaged she couldn't produce eggs(she can release yolks but those can't travel to the oviduct and fall in the body cavity and get absorbed by the body), just an occasional shell-less egg i caught her laying from the roost. Others had a slight change in the shape- texture of the shell but not noticeable, and the majority nothing at all. Symptoms subside in a short while, and the hen will live normally afterwards, but her eggs usually be different if damage has occured.... However now after the hens moulted and started laying like machines now in the beginning of spring, one of the hens that supposedly had a damaged uterus and frequently layed softshelled, mal-coloured eggs, and often laid them whereever she was standing, but now after her winter break, she's laying perfect eggs like the ones she layed before getting IB, and on the other hand, on hen that had the symptoms and recovered and her eggs were not affected, now is laying washed out eggs, with lots of bumps and a thinner shell....
So as you can see it's just my personal experience I'm talking about.... Hope all goes well with you and your birds!
There's a thread over here that covers all the reasons for a weird egg... Update us!
Thanks again!
