Pigeon breeder's lung.

In the acute form of pigeon breeder's lung, chest X-rays often reveal micronodular changes, but 7 of the 16 patients examined showed no changes. In the subacute form, chest X-ray changes are exceedingly rare: they occurred in only 1 of the 17 patients. Pigeon breeder's lung differs from the condition known as bird breeder's lung in that it turns much less often into a chronic condition (pulmonary fibrosis and emphysema).