10 INTRODUCTION 



poll-evil we have found to be much greater in 

 some localities than others. In some districts 

 it is actually an equine scourge, while in others 

 it is a rare occurrence. In southern California, 

 for example, veterinarians seldom if ever see 

 a typical fistula of the withers or poll-evil, while 

 in central Illinois it is a veritable horse plague. 

 In a recent conversation with an old horse 

 breeder in the latter location the information 

 was elicited that fistula was once as rare there 

 as in California. Asked if he had any theory 

 to advance as to the cause he seemed inclined to 

 attribute most cases to influenza, and colt dis- 

 temper, claiming that before these diseases be- 

 came prevalent from the interchange of horses 

 from shipping centers there were no cases of 

 fistula of the withers. The rarity of shipping 

 fever (influenza) in California, seems to add 

 logic to these observations. 



But no matter what the cause may eventu- 

 ally prove to be, the veterinary practitioner is 

 today confronted with a serious disease of 

 horses that he must endeavor to control and 

 handle to the better satisfaction of horse breed- 

 ers and the public. To fall short of meeting 

 this requirement is one more adverse reflection 

 on our ability to meet the demands of our 

 growing live stock industry. To study, to ex- 

 periment with, to strive to curb, and to analyze 



