I've done all I know to do, so help me out here.
I've got an old girl (4-5 years old maybe) white leghorn. When she was laying, she never had any issues. I really only remember maybe one or two double yolkers. My flock had always free ranged during the day 100% until a few months ago when I enclosed a fenced in area and moved them to a new larger, much better coop. They still had plenty of grass, sunshine, bugs, etc and I would let them out each night and let them wander for a few hours before bedtime. I also have always provided them with laying pellets, though not exclusively. They have mostly foraged for probably 90% of their intake.
A couple of months ago, I noticed that she looked fatter on the back end. Like I said, she's old so she hasn't been a regular layer for a while now so not getting any eggs from her (she's my only white egg girl) for a while didn't really spark any concern. She was acting normal, eating normal, pooping normal, etc. Off and on though, she looks like she's in discomfort and for the last few weeks, she's gotten worse and worse.
Virtually every weekend, I perform the egg-unbinding routine... very warm water, massage, olive oil and digital exam but nothing ever happens. I'll dry her off and put her back out with the others a day or two later. She'll look like she's doing maybe a little better (though never an egg) and then by the weekend, she's bad enough again that we do the whole egg-unbinding routine all over again.
I have examined her digitally (much more thoroughly than both of us were comfortable with) and I do not feel an egg or anything that resembles an egg. In fact, I can only seem to examine one "tract" I don't know if this is her digestive tract or her reproductive tract. But everything is very firm and super distended. If there's an egg in there, it's the size of a grapefruit now (which is obviously impossible.) I hope.
This week, she's gotten noticeably worse. She's having a very hard time walking and can no longer jump up on the roost or even up the chicken stairs that lead into the coop. She's still eating, still drinking and (I think) still able to eliminate. She doesn't appear to be in distress yet, but is definitely in an extreme amount of discomfort.
Being egg bound is my guess - all signs point me to that... no eggs for months; swollen, heavy rear; trouble walking; pulsing vent; droopy tail, penguin-y gait (when she could still walk) but if that's the case, she's been egg bound for a couple of months now and that doesn't seem possible. If she's egg bound, shouldn't she be dead by now?
A little while ago we just finished soaking for a couple of hours, fed her a TUMS, gave her lots of water (she ate a bowl of layer pellets) and examined her again - hate to be gross here but I examined as far in as I physically could. Her vent is not prolapsed and looks completely normal, aside from the giant bulge underneath.
Any other ideas? Tumor?