Pulmonary Function in Pigeon Breeders' Disease

Pulmonary function studies were performed in 13 patients with clinical and immunologic evidence of pigeon breeders' disease. In the nine subjects with the acute form of the disease the most consistent abnormality demonstrated was an increased residual volume. Two subjects had changes in arterial PO2 and dead space to tidal volume (VD/VT) ratios with exercise compatible with disturbance in ventilation-perfusion relationships. One individual had a low diffusing capacity at rest but a normal value with exercise. Studies of respiratory mechanics showed an elevated maximum inspiratory transpulmonary pressure in two subjects as well as a low static and dynamic compliance. Delayed reversible reductions in vital capacity and flow rates as well as changes in respiratory mechanics after exposure to pigeons were demonstrated in two of these breeders. In the two subjects with the subacute form of the disease the response to acute pigeon exposure was less dramatic, but restrictive respiratory impairment was present during chronic exposure and resolved slowly but completely with avoidance of pigeons. However, a nonreversible increase in pulmonary elasticity was demonstrated in one of these individuals. Nonreversible restrictive and obstructive respiratory impairment as well as disturbances in carbon monoxide diffusing capacity were found in the two patients with the chronic form of the disease. The most significant findings in this group were changes in respiratory mechanics that are identical to those found in pulmonary emphysema. From these studies it is apparent that permanent lung damage can occur in pigeon breeders' disease, particularly in its chronic form.