CHAPTER VIII. 



CONTAGIOUS DISEASES. 



1. DIPHTHERIA OR ROUP. 



Uiplilheria, croup or loaip, is a very common dis- 

 ease among' poultry, and undoubtedly destroys millions 

 of dollars worth ot fowls in tlie United States every 

 year. Tliere are two forms of roup, one caused by 

 bacteria and the other by pr&tozoa. but since the symp- 

 toms, remedies and means of 

 prevention are very much 

 alike in both cases it is not 

 necessary that they should 

 be considered separately in 

 this report. 



Roup is, in all cases, a 

 contagious or "catching" 

 disease. It spreads from 

 one fowl to another and 

 ma}' be carried from flock 

 to flock by the interchange 

 of birds. It is thought by 

 some that roup may be pro- 

 duced by exposure, and that 

 it is merely a severe cold or 

 catarrh, but careful observa- 

 tion shows that this view is 

 not cnrr(H't. and that roup 



(91) 



The Floor of the Mouth of 

 A Fowl, Showing Diphthk- 

 RiTic Patches. 



