CHAPTER I 



GENERAL METHODS OF CONTROLLING 

 DISEASE 



I. Importance of Controlling Disease 



THE ravages of disease add considerably 

 to the difficulties of raising poultry in 

 all parts of the world. It is the experience 

 of poultry rearers that an annual toll has to 

 be paid in the lives of young birds and older 

 stock. Sooner or later, in addition, an epi- 

 demic may break out and result in heavy 

 losses and much discouragement. 



It is most important, therefore, to be able 

 to recognize the symptoms and to know the 

 causes of the many diseases to which vari- 

 ous kinds of poultry are subject. Every 

 practical effort should be made to reduce 

 avoidable mortality. An unexplained 

 death should be regarded with concern. It 

 may point to the presence of a serious dis- 

 ease. When there is not sufficient external 



