488 



DIPHTHERIA IN FOWLS 



symptoms of it. There is a general belief that the disease maj- 

 be developed by exposure of birds to draughts of air or b}' 

 keeping them in damp, filthy and badly-ventilated houses. 

 It is presumable that this belief in its etiology is not well 

 founded because of confusion existing concerning the early 

 symptoms of acute diphtheria and those of all stages of the 

 chronic form, and those of simple colds and catarrhs. Ward 

 was Unable to produce the disease by exposing fowls to unfa- 

 vorable conditions, but when infected fowls were introduced 



Fig. 114. Fozi'l sho'cving the suborbital sinns distended. The eye is 



partially closed. 



the disease spread rapidly. Dampness and lack of ventilation 

 no doubt favor the maintenance of the virus when introduced. 



The specific cause of the disease known as diphtheria or 

 roup in chickens and pigeons, in the opinion of the writer, is 

 not known. It is not impossible that a number of organisms 

 may share in the production of the lesions of this affection. 



Guerin considers it a general disease caused by a cocco- 

 bacillus (resembling the fowl cholera organism). This is not 

 unlike the bacterium of septicemia hemorrhagica. He finds 



