DISEASES OF THE RESPIRATORY ORGANS. 15 



may be a diarrhoea, and where a number are affected 

 the sight is a very pitiful one. 



Causes: The cause of roup and diphtheria is a spe- 

 cific germ or bacteria; it is not yet positively decided 

 whether it is the same germ that causes human diph- 

 thea, but it seems the best evidence points that it is 



not; however, it is always well to take some precau- 

 tion. 



Overcrowding in filthy, dark, damp, illy-ventilated 

 poultry houses favors the development of the disease. 

 Prevention: Birds which have been at poultry 

 shows, or newly bought birds, should be kept by them- 

 selves, away from the healthy fowls for a period of 



20 to 30 days, in which time the disease would develop 

 if they were affected. 



The discharges from diseased fowls are loaded with 



germs which dry and become disseminated through 



the air and dust and are breathed into the air passages 



of healthy birds. Fowls which have recovered from 



roup should not be kept for breeding purposes, because 

 their progeny are often weak. 



Treatment: In the first place, the healthy birds 

 should be removed to a non-infected place where the 

 sanitary conditions are good. Poultry, animals, or 

 persons should not go direct from infected pens to a 

 healthy flock. Thorough and persistent disinfecting 

 of the poultry houses, roosts, feeding troughs, drink- 

 ing vessels, etc., is absolutely necessary both where 



sick and well are kept. (See article on germs and 

 disinfectants, page 9). 



