Moulds, fungi & yeasts are present in the atmosphere, especially in damp environments - Just try leaving damp bread out on the kitchen work surface & within a couple of days you will see a mould growth on the bread!
Poorly ventilated lofts & feeding damp musty feed can indeed increase the risk of your birds, do not feed brewers yeast to unwell birds as this may exacerbate the condition.
- Avoid stressful conditions.
- Avoid a warm stuffy loft with a damp atmosphere. Provide plenty of ventilation.
- Use Virkon S in the drinking water at the rate of half teaspoon to a gallon of water. This will kill any fungi, bacteria & viruses in the drinking water. The loft can also be sprayed out with a solution of Virkon S.
- Cider Vinegar in the drinking water kills fungal/yeast spores & is thus beneficial to the pigeons.