Thanks for advice. As for the vets, these are not pet birds, I simply can't justify the vet costs for a chicken. Sorry to be brutal.
Anyway, now for a full update. Started to administer Citracidal with a pipette yesterday, morning, lunch and afternoon. Also gave a small amount of aspirin dissolved in water. This morning you would never know the bird had been ill. Still keeping up the dose today and will reintroduce tomorrow. I have used Citracidal before and it seems to work wonders. I thoroughly recommend it
Phew!