Urgent! Upon soaking found a massive swollen area.

[chickdiane10]

She started limping about 10 days ago and I have her inside. Eating fine, standing on one leg and hopping around. I gave her a soak today and when I was drying her feathers I noticed this toward her back end on same side as the leg she is limping on. I wish I saw this sooner, I feel terrible!
What can I do? I have amoxicillin and Tia gard.

 

[Certified Chicken Lover]

How old is she? What her diet? It’s a little hard to tell exactly where the bump is on her body do you mind taking another picture of her whole back?

@Wyorp Rock @Eggcessive @azygous

 

[chickdiane10]

How old is she? What her diet? It’s a little hard to tell exactly where the bump is on her body do you mind taking another picture of her whole back?

@Wyorp Rock @Eggcessive @azygous

She is almost 6 months old (got as chick Aug 1st). Has not laid yet.
Feed: Broiler/grower new country organics (no soy). Just got layer feed today to start mixing in, bar ale, (on chewy). She has constant access to grit and oyster shell. She ate 1/2 a scrambled egg not long ago.
She's energetic, alert, stands on good leg, eats well.
BUT....she has lost 2 same age flockmates this month. I have a post on them and more back history. I'm new to the forum but will try to get the link to add here. This girl is in the post I made last night too (Peach), but I had no idea what was brewing under her feathers until I soaked her today

 

[chickdiane10]

Her poop was different today too. She had this while soaking. It looked like rat poo pellets in size/shape.

 

[chickdiane10]

More background story
https://www.backyardchickens.com/th...s-died-only-commom-thing-wzs-wasting.1607656/