My 5 year old hen has a "growth" below her vent that is collecting maggots and flies and she seems very swollen. I have washed her off several times with the hose, trying to make her more comfortable. I know I will lose her, but I want to know what this is. She just started laying again about a month ago, so wondering if it is a impacted egg? I can handle pretty much any gross animal situation, but this one is a tough one. She has a bad odor also. Any ideas?