Prevention and treatment of the disorders caused by 

 horse bots concern thousands of horse owners in this 

 country. In 1972, the total horse population in the United 

 States was approximately 7,000,000 animals. Of this num- 

 ber, about 2,739,500 were farm horses and mules; and 

 about 4,260,500 were nonfarm or light horses. 



Although the number of draft animals has declined 

 steadily since the advent of the tractor, maintaining the 

 health of draft animals still in use is vital in many areas. 

 And the increasing popularity of light horses has created 

 new demands for information about horse health. 



To meet the needs of horsemen for help in controlling 

 horse bots, the U.S. Department of Agriculture publishes 

 this leaflet. 



This edition replaces all previous editions of this publication. Because of changed 

 insecticide recommendations, earlier copies should be destroyed. 



