BUREAU OF ANIMAL INDUSTRY. 73 



considerable alarm, owing to its close resemblance to that disease. 

 Furthermore, as most writers state, this infection in cattle may be 

 readily confounded with foot-and-mouth disease, and experience 

 has shown that a prompt and exact differentiation is accompanied 

 by numerous difficulties. 



The principal differences between the two maladies may be stated 

 as follows: Horses are especially subject to vesicular stomatitis, but 

 have not been observed to contract foot-and-mouth disease in out- 

 breaks of the latter in the United States. Hogs and sheep, on the 

 other hand, are susceptible to foot-and-mouth disease, but have not 

 been observed to contract vesicular stomatitis under natural condi- 

 tions. Foot-and-mouth disease, once introduced, quickly affects 

 practically 100 per cent of the cattle and hogs on a farm, while 

 vesicular stomatitis spreads to a much smaller proportion of the cattle 

 and is not readily transmitted except by immediate contact. Certain 

 differences in the symptoms and lesions of the two diseases have also 

 been noted. 



The real difficulties surrounding the diagnosis are best ap- 

 preciated by those who have faced them with the consciousness 

 that their pronouncement if mistaken would lead on one hand 

 to unnecessary and serious economic disturbances and on the 

 other to the spread of one of the most dreaded and easily com- 

 municated among animal plagues. Vesicular stomatitis will there- 

 fore prove a menace whenever and wherever it may reappear. For 

 these reasons it is strongly urged that local quarantines to prevent its 

 spread be imposed by State live-stock officials in whose territory the 

 disease may be found. All owners and handlers of horses, mule's, and 

 cattle, particularly liverymen, managers of stockyards, and stock- 

 men, should be directed to separate sick from well animals, clean 

 and disinfect contaminated premises, and have all infected animals 

 appropriately treated. 



ANIMAL HUSBANDRY DIVISION. 



George M. Rommel, Chief. 

 ANIMAL HUSBANDRY EXPERIMENT FARM. 



The work at the experiment farm of the bureau used by the Ani- 

 mal Husbandry Division, at Beltsville, Md., has been continued as 

 heretofore. Work has been done in the construction of sewers, the 

 laying of tile drains, and the improvement of the farm roads. The 

 hog house was equipped with individual feeding pens and the small- 

 animal breeding laboratory was remodeled and greatly improved. 

 An entrance gateway was erected at the main farm entrance, and a 

 contract was let for the construction of a barn to replace the sheep 

 barn destroyed by fire two years ago. 



. ANIMAL GENETICS. 



The study of inbreeding continues to be the main subject of investi- 

 gation in the work on animal genetics. At present 15 families of 

 guinea pigs are being used, which trace back by exclusively brother 

 and sister matings to 15 original pairs. Some are in the seventeenth 



