My hen is worse than ever now. She's extremely lethargic and won't even stand on her own. When I found the maggots earlier I read on one of the threads that the thing to do is clean the area with soap and water, remove as many maggots as possible and then put SWAT on the wound to prevent any new fly problems. I had heard that maggots were good for cleaning a wound but that they could also carry diseases and that once they had eaten away the dead tissue they'd start on the living tissue (someone called it "flystrike" in another thread). Well, I didn't take any chances, not sure if this was true or not, but I cleaned the wound, removed maggots and caked on the SWAT.
The part I feel really horrible about (well, I feel horrible about the whole thing, but still), was that I was trying to examine the wound and since it's under her vent that's hard to do from the ground, so I lifted her by her legs like I've done a million times to my chickens when I dust them for bugs and inspect them. But when I did it, she threw up A LOT of liquid, and when I immediately put her down she would not stand at all. I think she may have aspirated some.
Unfortunately, I have no vet I know of to ask about avian problems, but tomorrow I will call my cat/dog vet and ask about the safety of betadine or triple antibiotic ointment on chickens and see if he knows anything. I've called around but never found an area vet that does chickens or birds of any kind. Tomorrow I will clean the wound again and see how it looks, but by the smell of it I can bet it's infected. The area around the ulcer is very red and angry too.
I thought about putting her down, but I just don't have the stomach for that. :( If she's still this bad tomorrow then I will probably have to, but I'm holding out hope that a good, quiet rest period might bring her back out of it. I've never had to kill one of my hens before, they're kind of just "pets" with an egg bonus. I would hardly know how to do it, let alone the fear of doing it incorrectly and causing her pain.
Thank you all for your advice. I am just waiting out tonight and seeing how she is in the morning. The guilt is really overwhelming, I feel like such a bad chicken mom. :(