344 ANNUAL REPORT SMITHSONIAN INSTITUTION, 1952 



The disease which was then known as murrain, or splenic fever, or 

 Texas fever, caused great consternation among livestock producers, 

 especially in the northern States, who saw their animals stricken and 

 die when they followed the trails of apparently healthy cattle that 

 had been driven northward from Texas and elsewhere in the South. 

 So great was the fear among northern cattle owners of the danger to 

 their herds from southern cattle that rigorous action was taken, some- 

 times accompanied by threats of violence, to prevent cattle from Texas 

 from being driven over the trails which led to the northern markets. 

 Another parasitic disease, known as sheep scabies, was ravishing flocks 

 on the western ranges. On account of the highly contagious nature 

 of this skin disease, the importation of sheep from the United States 

 to other countries was barred, and in this country the disease was 

 spreading as a result of the uncontrolled movement of livestock. 

 Cattle scabies, too, lurked in the background as a disease requiring 

 serious attention, if the increasing herds were to be maintained on a 

 high level of efficiency. The internal parasites of the country's live- 

 stock were practically unknown at the time the Bureau of Animal 

 Industry was established. However, one parasite of swine, Trichinella 

 spiralis, was well known in this country, and abroad it was regarded 

 as exceedingly dangerous on account of its potential harmful effects 

 on human beings. By 1881 several countries in Europe had already 

 placed an embargo on pork from this country, and the Department 

 of State instituted, therefore, an inquiry to ascertain the causes 

 that might render this meat dangerous to human health. 



These, then, were the principal known problems in parasitology 

 in relation to an expanding livestock production that confronted the 

 Bureau of Animal Industry in 1884, when Salmon and his few assist- 

 ants began "to provide the means for the suppression and extirpa- 

 tion" of disease of farm animals. The manner in which the Bureau 

 fulfilled its responsibilities, the investigational work that had to be 

 carried out before suppression and extirpation could be undertaken, 

 the means adopted to carry out the programs, and the success achieved, 

 constitute an important and fascinating chapter in the history of 

 livestock hygiene and disease prevention. Only those parts of the 

 chapter which relate to parasites and parasitic diseases can be re- 

 viewed in the course of this address, and only by a few outstanding 

 examples. 



TICK FEVER 



Although it is uncertain when the disease now known as tick fever, 

 or bovine piroplasmosis, was first introduced into the American col- 

 onies, it is probable that it came in with importations of cattle from 

 the Spanish West Indies and Mexico, perhaps sometime in the seven- 

 teenth century. By the end of the eighteenth century the disease was 



