342 AGRICULTURAL BACTERIOLOGY 



expiration of two weeks, provided the house and other con- 

 taminated objects have been thoroughly disinfected. 



Fowl typhoid. This disease is often mistaken for 

 chicken cholera. It is, however, produced by a different 

 organism. The disease is less rapid in its progress in the 

 individual bird than is cholera. The diarrhea so character- 

 istic of cholera is absent, and the intestines are pale in- 

 stead of deep red, as in cholera; the contents are normal 

 in consistency, while in cholera the intestinal contents are 

 liquid and blood-stained. The blood is free from the or- 

 ganisms. It is not especially important that a correct diag- 

 nosis be made as to which of these diseases is present in 

 the flock, since identical methods of prevention should be 

 employed with either. Cleanliness should be the chief re- 

 liance of the poultryman against these diseases. 



Roup. Roup, or diphtheria of fowls, is considered the 

 most important transmissible disease affecting the barn- 

 yard fowl of this country. It occurs in turkeys, ducks, 

 pigeons, and pheasants, as well as chickens. The cause of 

 roup has not been discovered, and it is not certain whether 

 chickenpox and canker are different diseases from roup 

 or different manifestations of the same disease. 



It has sometimes been considered that this disease has 

 some relation to diphtheria in man. There is no reason 

 for such belief other than that in certain forms of roup 

 there may be formed a membrane similar to the membrane 

 noted in diphtheria. The first symptom of roup is a 

 watery discharge from the nostrils and often from the eyes. 

 The bird becomes dumpish; the breathing is often noisy, 

 due to the obstruction of the air-passages by the exudate. 

 The fowl may be able to breathe only by opening the beak. 

 Sneezing is frequent. The eyes may be covered with a dry 

 discharge, or they may be forced from the sockets by the 

 accumulation of cheesy matter in the sockets. There may 



