Greetings
Jnyhrnza,
My dear Filamena, had a hernia for a year. It was caused by swelling from ascite build up. She had about three or four remissions during that year. When her swelling resolved, she'd be fine and ran around with the flock happily. And when she was swollen, she was fine and ran around with the flock happily, too.
But, I did have to manage her condition for the year. A chicken doesn't know what's good for them. We placed tree stumps around the yard so she could follow the flock, when swollen. Sometimes I penned her up in the patio to protect her. Then, I made her a truss that attached to a saddle. That truss protected her herniated belly, while she was out.
It was a lot of work, as, I also had rooster that adored her. So, I had to monitor him and even isolate him from her. A hen with a hernia and/or ascites can not breed. There are many dangers for hens with hernias or even just ascites. You are right, rupture is a huge concern. Because of this, the hen can no longer jump up or down from the perch. The perches have to be lowered, or the hen has to sleep in a small dog crate.
In the end I made the heart breaking decision to euthanize Filamena. She had an obstruction that caused her to become very ill. But, she had a wonderful chicken life for one more year.
I am retired, so I had the time and resources to accommodate her condition. It was a learning experience for me. Since then, I have had two more hens with swollen bellies. One passed away quickly, from a ruptured egg in her coelomic cavity. The other hen, is still with me. I learned how to care for these hens more efficiently, and provide treatments that allow them to have quality of life. In fact this hen has just healed after being swollen for 5 weeks. But, I still have to monitor her, and always will till she eventually dies.
My chickens are pets, so the things I do for them are unique to my chicken keeping preferences. If you have small children, or work all day, it may not be feasible to care for a hen with a hernia. This is understandable. Take the time you need, to decide what is right for you.
These are my thoughts on your hen's issue. I hope I have been helpful.
God Bless