Hi Manun2a, please dont take this the wrong way, but you do hold the bird like hes a chicken, are your pigeons kept along side or near chickens ? If they are i would seperate them stright away as some lice/mites are spred by poultry. Open the birds wing up and look at the underside against the light, you may be able to see them.
Im not saying that it is mites or lice but it where i would start.
Ive found this link i hope it helps.......
http://www.chevita.com/en/pigeons/treatment-plan/parasites-ectoparasites.php
if you have a vet near you i would also take him there.
sorry i could'nt be more helpful and i hope he gets better
all the best
Amanda
ps could you take some pictures of the feathering.
pps male pigeons go on top