My sweet hen, Kua, passed away this July from Ovarian Cancer. She was a "Golden Comet" which is a fancy term for a sex-linked production hen (I didn't know this when I got her, I had only read that they made sweet pet hens). Though I never use supplemental light for my birds in winter, she didn't slow down on her laying duties, even once, since the time she came into lay. She laid large eggs almost every day of her life after she matured. She only molted once, even though she was more than three years old. In late May, I noticed she had stopped laying. I was desperately hoping that she was just coming into molt, but I have learned enough about production hens to be suspicious. In July I noticed a small mass in her abdomen (I was checking her daily). I made a vet appointment, hoping to catch any problems early and maybe even use a hormonal implant. By the time her appointment rolled around a week later, the mass in her abdomen was huge and she was markedly less spunky. My vet took x-rays so we could try to determine the nature of her problem, though we were both pretty sure it was reproductive, given her age, breed, and symptoms. Please ignore the vertical bands on the image; those are from the flicker rate of the light being picked up by my camera. They are not present on the actual x-rays. Of special note are how "bright white" some of her bones look on the x-ray. This was more evident in person.. these photos were not the best. I took these after she passed away and I was a crying mess. I digress- The bright white on her bones, most especially her long bones and spine, were of great concern to my vet (look carefully at the first x-ray, at her vertebrae especially). It is caused by bone marrow ossification which is secondary to a spike in estrogen. She usually only sees this in birds that are about to lay an egg (which my hen was not about to do) or in those that are experiencing reproductive tumors. From Laferber's Veterinary page: Quote: Source: http://www.lafebervet.com/avian-medicine-2/avian-emergency-medicine/reproductive-emergencies/ Also of note is how far the mass was pushing organs out of their typical locations. For comparison.... Here is an otherwise healthy hen's x-ray (save for the piece of metal in her gizzard, which she safely digested): This photo is NOT MINE and is used for education only. It is from the following page: http://winonafarmsinc.blogspot.com/2011/04/indesctructable-chicken.html The x-ray couldn't give us a full picture and I still held some hope that we could do something for her. Luckily, my vet has a portable ultrasound that is somehow configured to image birds well, and we did the ultrasound. It was quite inexpensive (much less than x-rays). It told the rest of the story-- and, I may have the screen captures from this someday when the vet has time to save and send them over to me. There was no fluid buildup, but clear non-homoginized little tumors all through her intestinal tract, and ovaries. The vet explained that even if we tried surgery, that once they are all into the intestines there is no hope of extraction. Then we slid the ultrasound wand over to look at her liver, and it was non-homogonous too. Meaning mottled; full of tumors. There was no hope. There was no fluid to drain, and no implant that could possibly reverse this much damage. It had grown very rapidly. Here is Kua on her last day with us, at the vet's office. Notice how she looks a bit lethargic, and her posture. She was usually very alert, spunky, tail held high, and trying to eat our fingers. This is still a hard photo to look at. She was a very good hen, and a good friend. If you view the reading below, in the first link there are photos. My hen's innards looked like Photo "B" (Primary malignant ovarian tumor in laying hen with stage IV OvCa.). I am not as well studied in this as I am Marek's... but for those that might want to learn more, here is some additional reading I found on a few passes of google. Kua was a great hen and we miss her dearly. Her fate is one that many (some might say "the majority") of production hens meet, and it is common between the ages of 2-3 years old. It is something to consider when looking at which breeds to get, if you are not concerned about egg production and are looking for pet hens, like I was. She was an excellent egg layer, but I'd trade that to have her with us for several more years. Reading: http://www.nature.com/onc/journal/v33/n28/fig_tab/onc2013321f3.html - this one has images of tumors with explanations in the caption. They are graphic but educational http://www.plosone.org/article/info:doi/10.1371/journal.pone.0057582 - This also has images. You can zoom in on them. http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1474556/ http://www.jstor.org/discover/10.2307/3430596?uid=3739832&uid=2&uid=4&uid=3739256&sid=21104264863121 http://cancerprevention.aacrjournals.org/content/2/2/97.full RIP sweet Kua. I hope this information helps someone, someday. Unfortunately, once it is at this point, there is no cure or treatment. Love your hens while they are still with you!