Rooster with a crooked neck

[Peanut_better]

This is how neck normally looked like

And this is how his neck looks like now.
His head is tucked into his feathers and leaning to the right side. He doesn't appear to have any other symptoms other then he's eating and drinking slowly and he doesn't feel like going outside. He also hasn't crowed in like 2 weeks. But he can still jump up to his perch and doesn't feel like he's lost weight yet.
I just had to cull one of my hens that I had housed with this rooster on Oct 15 because she was sick. However this hen had more severe symptoms such as not being able stand up and walk. But she didn't have her neck like this rooster. There's also 2 more hens housed with this rooster too but they appear to be just fine.
Any advice will be greatly appreciated.

 

[Eggcessive]

I would be a little worried that he might be showing signs of wry neck. Wry neck is a symptom of several conditions such as Mareks disease, head or neck injury, genetics, or vitamin E deficiency. Most people treat with vitamin E 400 IU along with a little chopped egg and B vitamins for a couple of weeks to see if there is improvement. If you should lose him or if he becomes lame in one leg, I would keep his body cold, and ship or take it to your state poultry vet for a necropsy and testing for Mareks.

Normally, wry neck can be common in chickens, and they may also walk backward or in circles, but since you lost a hen recently with lameness. Do you know if your birds were vaccinated dor Mareks? Here is some reading about Mareks:
http://csu-cvmbs.colostate.edu/Documents/vdl-mareks-disease-fact-sheet.pdf

 

[Peanut_better]

I would be a little worried that he might be showing signs of wry neck. Wry neck is a symptom of several conditions such as Mareks disease, head or neck injury, genetics, or vitamin E deficiency. Most people treat with vitamin E 400 IU along with a little chopped egg and B vitamins for a couple of weeks to see if there is improvement. If you should lose him or if he becomes lame in one leg, I would keep his body cold, and ship or take it to your state poultry vet for a necropsy and testing for Mareks.

Normally, wry neck can be common in chickens, and they may also walk backward or in circles, but since you lost a hen recently with lameness. Do you know if your birds were vaccinated dor Mareks? Here is some reading about Mareks:
http://csu-cvmbs.colostate.edu/Documents/vdl-mareks-disease-fact-sheet.pdf

Thank you for responding. Some of my chickens were born in my backyard so they weren't vaccinated. However this rooster alongside 2 other chickens I bought from breeders and I wasn't told if they were vaccinated and unfortunately I want aware of Marek’s disease so I did not think to ask.
I also forgot to add that my rooster has showed signs of being lethargic for almost 2 weeks now however he would still court his hens and chase them around the yard so I thought it was just me worrying too much. He didn't show his wry neck until Oct 13th.
Also for the hen I culled, her symptoms came fast. It's started on Oct 10th with her right eye being half closed but she never appeared to be blind. Then the day after she started crouching like she wanted to lay an egg but she never did. Then the day after that she started limping on her right leg. Finally on the 13th she lost control of both of her legs. So I decided to cull her on the 15th.

 

[Eggcessive]

Unfortunately, that does sound like the hen had Mareks, but it is hard to ever know if it could have been something else without testing or a necropsy. Wry neck can be a common symptom though and possibly unrelated. But some with Mareks may have wry neck. He is a cute little rooster, and I hope he recovers. Your state poultry vet can be found here:
https://www.metzerfarms.com/PoultryLabs.cfm
There also is vetdna.com which is a lab that does a mareks test on blood serum from live birds for about $20 if you contact them for information.