Rooster unwell. Cocci?

[Altairsky]

This morning I noticed that my 7 months old cockerel is unwell.
Hi doesn't tidbit for the ladies. This is not normal.
I observed him and he's less active with a sad looking tail.
He still crows and mate.
His crop is not empty but there is not much food in there. He's not interested in food. He ate a bit of egg, and a bit of yoghurt.
I isolated him to see if he could poop and I think it might be cocci. He only pooped twice in 5 hours.
I gave him oil just in case, and added bird vitamins to the food.
I have both amprolium and sulfa at home. I attach pictures of the poop and medicines below with a few questions.

 

[Altairsky]

There is no corid in my country, what is the dose to administer directly in the mouth? It says amprolium 100mg per 1ml.
Should I keep him warm tonight? It's around 0°C here.
Should I treat all the flock or just him?

I also have sulfa available but maybe it's better if I try amprolium first?

 

[arianna7]

amprolium is often around 10% of the body weight in mg per day for 5-7 days you can look up different ways to give it to him but i just would use a syringe.

defenatly keep him warm, and dry! and if hes staying with your hens i would treat ur girls too!

 

[Altairsky]

Well I'm dumb. It's literally written 7 drops per kg (0,35ml) in the box.

 

[arianna7]

Well I'm dumb. It's literally written 7 drops per kg (0,35ml) in the box.

ok, i would do that then

 

[Altairsky]

He is 2,5 kg for a 7 month legbar, it's not a bad weight so I kept him outside. He will be happier to be with his girls and he's not to the point of starvation atm. I closed him inside a nest box together with his favorite pullet so he can stay warm.
He had 0.8 ml of amprolium this evening and I'm treating the whole flock with medicine in the water.
He had an empty crop this evening. He still crows from time to time and he still mate the girls but not with his usual energy.
I really hope he gets better, the girls really love him.