What's Causing My White Chicken's Perpetually Dirty Rear End?

[farmgirlsomeday]

I hope this is the right place to post this question. I have a beautiful white and salmon colored Easter Egger named Birdie. By all evident measures, Birdie is very healthy. She's a good weight and she eats and drinks well. She's active and curious, and she routinely lays 5-6 pretty blue eggs each week. However, starting several weeks ago, I've noticed that her hind end is filthy all the time. Here's a photo I snapped of her walking away from me so you can see what I mean.

I keep a scrupulously clean coop and run, including nest boxes, and Birdie is also allowed plenty of free range time in our fenced backyard. Yet her bum remains super dirty. I have one other white chicken, a Silkie, and she is never dirty like that around her vent and hindquarters.

I'm worried that something is wrong with Birdie that I'm not aware of, and so I can't address it. Any ideas as to what could be causing her to remain filthy in her tail area like that?

Many thanks.

 

[Kelsie2290]

I would wonder about vent gleet, BYC article on it https://www.backyardchickens.com/a/vent-gleet-aka-nasty-chicken-butt ... Can you give her a bath / trim the feathers and check her over really well? Has she been wormed? Have there been any changes in her diet?

 

[farmgirlsomeday]

@Kelsie2290 thank you so much for this suggestion, and the link to the article. She is already getting ACV in her water, but I'm going to wash her (which should be interesting; I've never tried washing one of mine!) and trim her feathers back, as well as try the other recommendations. I'm also wondering about worms.