seen the exact same thing in pouters a number of years back the man took them to the vet and salmonella /paratyphoid was the diagnosis ,the pupil had completely dissapeared
blue to mealy is sex linked all mealys will be cocks and all blues will be hens but as in everthing else pigeons there is not gurantee that you will breed all mealys
before anything gets shoved down the birds throat it would be better to remove the feeding from the crop this is whats causing the sour crop in the first place clear that then all is well
its also good publicity for us as well when this happens just think on it someone sitting in the cafe having a nice meal and along comes mrs sparrow hawk tearing a pigeon to bits entrails all over the place yuk how long do you think they will put up with that