I have a question

[Granny23]

I have a 2.5 yr old RIR hen who has a swollen, rather firm, warm to the touch under belly.
I found a really weird looking thing in the nest a couple weeks ago and I'm finding pieces of soft shells or eggs with no shell.
She acts fine, she's eating, dust bathing etc.
My granddaughter picked her up yesterday and felt the swelling.
What can I do,if anything, to help her and what is causing it?
Thank you

 

[azygous]

If the swelling is behind the legs and just below the vent and coupled with the report of odd things coming down her chute, there's a possibility she has a reproductive infection. An antibiotic would be in order.

If she has the majority of the swelling in front of and between her legs, then it points to liver disease.

 

[Granny23]

If the swelling is behind the legs and just below the vent and coupled with the report of odd things coming down her chute, there's a possibility she has a reproductive infection. An antibiotic would be in order.

If she has the majority of the swelling in front of and between her legs, then it points to liver disease.

Thank you!
It's in the back between her legs below her fluffy butt. What kind of antibiotics can I use and does it require a vet visit or can I get something at the feed store? Anything else I can do for her?

 

[azygous]

https://jedds.com/products/enrofloxacin-10?variant=40215712661693
Dosage is 10 mg per every 2.2 pounds twice a day for 5 days.