Hi guys I am in contact with the British Hen Welfare Trust in the United Kingdom and we were emailing about my dissertation idea which might be something on egg peritonitis (i have decided exactly what yet). However the vet who works with them suggested to me that Suprelorin implant (Virbac), which is used on dogs to prevent aggression, can be used to stop hens secreting egg material which leads to egg peritonitis. It is a chip that is implanted into the neck of a chicken and releases hormone signals which prevent any more eggs from being laid! ... the chip lasts a year and so needs to be replaced and apparently costs around £40 to £50 (don't know if its in USA or anywhere else). It is not licensed for use in chickens though so this might be what I may be working on for my dissertation. Also it means you do not have to spay your hen, and I'm not entirely sure yet, but i assume no antibiotics will have to be taken (i read another thread where they were talking about antiobiotics being used to stop egg laying). Just thought I would post and see if anyone has any views on it. let me know what you think!