Diseases of the Respiratory System 179 



of the lungs are filled with clotted serum. The first form of 

 the disease is called broncho-pneumonia. In these cases 

 death from sufl^ocation has taken place while the vascular 

 area of the lungs is little affected. This is the form of the 

 disease which usually follows bronchitis. There is usually 

 also some clotted serum in the smaller passages. The second 

 form is known as croupous pneumonia. This form usually 

 follows congestion of the lungs and often develops very soon 

 after severe chilling. The lungs are dark in color and solid. 

 The blood vessels are filled with blood and the air spaces are 

 filled with clotted serum. A piece of such a lung will sink 

 when dropped into water. 



Etiology. — The cause of pneumonia in birds is not known. 

 The similarity of this disease to human pneumonia, both in 

 the circumstances of its occurrence and in its lesions, has led 

 to the inference that the cause is also similar. The disease is 

 probably caused by a bacterium which is very often present 

 in the normal air passages but which is harmless except when 

 there is congestion. 



Treatment. — Ordinarily it will not be advisable to treat 

 this disease. A cure is unusual and involves such an amount 

 of care and nursing as to mahe it a most unprofitable proposition. 

 The disease can be guarded against by keeping the flock in 

 good condition and preventing exposure. Some cases will 

 recover if removed to a warm well ventilated room and fed 

 milk or raw eggs supplemented later, if the bird improves, 

 with cod liver oil and chopped beef. 



Various medicines, especially stimulants, have been recom- 

 mended. One drop of tincture of aconite every two hours 

 given in egg or milk is said to relieve the hard breathing. As 

 a stimulant 2 drops of spirits of camphor and 10 drops of 

 brandy in a teaspoonful of warm milk may be given 3 or 4 

 times a day. If the comb becomes dark and the bird is 

 evidently failing rapidly add one drop of tincture of digitalis 

 to the above medicine. 



