Rooster losing weight and neck feathers

[PeepingK]

I have no idea what’s going on with my poor boy Rowan. This past month or so I’ve noticed that he’s lost a noticeable amount of weight and I can’t figure out what it’s from. Every night I lock them up I feel his crop to see how much he’s eaten and it’s usually less than half as full as the girls he has with him.
I treated him with Ivermectin for mites and lice (the vet told me it would also deworm him but I’m heard contradicting things about that online). I also have Aquasol on hand but I’m kind of confused on the dosage since I only want to deworm him and not the rest of the flock.
Another thing, couple weeks ago I noticed that his chest feathers looked a little ruffled on him. 2 days later his neck feathers started looking pretty chewed up as well. Now here we are 2 weeks later and almost all his beautiful hackle feathers are chewed in half . The skin around his neck does look a little red but I couldn’t see and mites or lice there.
Is he getting picked on by the girls? Or could this be linked to his weight loss somehow?

First picture is him a couple weeks ago, second is him a few days ago.. and it’s gotten even worse since that last pic was taken.

Any advice would be greatly appreciated!

 

[nuthatched]

It could be picking from the girls, what's their diet? Or depluming mites, which are microscopic.

 

[PeepingK]

It could be picking from the girls, what's their diet? Or depluming mites, which are microscopic.

I treated him with ivermectin for mites over a week ago but it’s only gotten worse. A few weeks ago I noticed one girl picking at his feathers but I haven’t seen her or anyone else do it since so I have no idea if he’s doing it to himself or not.
I feed them 18% layer feed.

Here’s a picture from a couple nights ago.

 

[coach723]

Feather picking often happens on the roosts at night. I see broken feathers, so I suspect one of the girls is doing it to him. Depluming mites usually cause them to pull their own feathers, and that area of the neck would be hard for him to do that.

 

[PeepingK]

Feather picking often happens on the roosts at night. I see broken feathers, so I suspect one of the girls is doing it to him. Depluming mites usually cause them to pull their own feathers, and that area of the neck would be hard for him to do that.

I think I figured out what the problem is. We’ve had a rat infestation for months now and have been having a really hard time getting rid of them all (I’m talking hundreds) since we live on a farm and have lots of building that they can make their nests under. Anyway, they’ve been coming into the coop through the top almost every night and I have a feeling that they’ve been the cause of my boys feather loss. I searched it up online this morning and found that some people were having issues with rats chewing off the feathers of their chickens.
I’m guessing that they’ve also been the cause of the relentless mites that we’ve been dealing with since last year July

My poor boy is looking worse and worse by the day.