hi geordiejen, i thought mine had yb sickness the other week but it turned out they didnt...........they had a bacterial infection which made them sometimes be sick and were off their food, the birds were hunched slightly and seemed to be loosing a bit of weight.....the droppings went slightly loose but were not watery all over the floor.
i gave mine three tablets one per day for the infection and a probiotic for the bacteria in the crop/gut, maybe yours might not have the yb sickness and might be something similar to what mine had.......i dont think me letting the birds peck around in the garden did them much good.