Diseases of the Respiratory System 111 



are taken into a closed room, where the tar water is poured, 

 a small quantity at a time, on a hot brick or stone until the 

 atmosphere of the room is well charged with the vapor." 



This treatment is of value only when the lesions are of the 

 open type first described and when these are located in parts 

 of the air passages accessible to the fungicides. 



Prognosis. — The disease in adult fowls is ordinarily not 

 recognized as such until an affected bird comes to autopsy, 

 at which time the prognosis is certainly extremely unfavor- 

 able. So far as concerns ridding a poultry plant of the dis- 

 ease, however, the outlook is favorable if energetic sanitary 

 measures along the lines indicated above are applied. 



Congestion of the Lungs 



Congestion of the lungs is a distention of the blood vessels 

 which make up the vascular portion of those organs. The 

 pressure of these distended vessels may close the smaller air 

 passages, or a vessel may burst, filling the bronchi. In either 

 case the patient soon suffocates. 



Diagnosis. — The symptoms of this disease are difficult 

 rapid breathing, sleepiness and an indisposition to move. A 

 bloody mucus sometimes flows from the mouth. The comb is 

 dark red or bluish from lack of ox^'gen in the blood. Symp- 

 toms appear suddenly and death occurs within a few hours. 



Etiology. — This disease is caused by chilling the surface of 

 the body. This contracts the surface vessels and a large 

 volume of blood is sent to the internal organs. The pressure 

 on the small elastic vessels of the lungs is too great and they 

 either close the air passages by pressing against them or the 

 vessel walls are ruptured by the internal pressure and the air 

 passages become filled with blood. This disease most often 

 occurs in denuded birds (hens during molting or young birds 

 which have failed to feather out) or small chicks which have 



