Prolapsed Vent on Chickens
Most hens are able to lay eggs with no problem. However, some hens develop something called a prolapsed vent, which happens after an egg is laid. The vent, or oviduct, turns inside out and hangs outside her body. She will need attention right away.
Jesse Lyons is an extension poultry specialist at the University of Missouri. He says a prolapsed vent is not a common occurrence, but can happen for several reasons: the hen passes a very large egg, she's too young, she's overweight, or she's genetically susceptible. He says research shows hens that are fed adequate calcium are less likely to have the problem.
"The calcium I think has some influence upon the muscle stimulation and the strength of the muscles of the bird. That's kind of a theory, anyway," says Lyons. "Some of the recommendations are to feed large particle-size calcium such as oyster shells, or top-dress the feed with oyster shells to get large particles into the gizzard, so that that will flow out of the gizzard so she has an intestinal source of calcium."
Lyons recommends keeping the nest boxes in a dark area so if a hen develops a prolapsed vent, the other chickens won't see it and peck at it. Check your birds periodically after egg-laying. If you see a prolapse, take immediate action.
"I've had prolapse in a bird, and got her separated and cleaned up a little bit, put into a very clean environment because her prolapsed vent is there," says Lyons. "In a couple day's normal feeding, it did retract back into her body. But, I watched this bird through the next laying cycle and she never did lay very many eggs."
If you look online, you'll find all sorts of remedies for a prolapsed vent, including pushing it back in yourself, and using a hemorrhoid cream. Unfortunately, once a bird goes through this, it's likely to happen again.