ELEVENTH ANNUAL YEAR BOOK— PART X 555 



greatly reduced by starting early in the spring and reporting 

 every outbreak as soon as it appears. 



The plant used for the manufacture of serum consists of a labor- 

 atory, shelter pens, crematory and necessary buildings constructed 

 according to plans and specifications designed with special refer- 

 ence to the requirements of this work. 



The tract is divided into five and ten-acre lots and fenced with 

 woven wire fencing separated by alleys for the segregation of im- 

 mune and susceptible hogs. 



In constructing the laboratory we have, as nearly as possible, aim- 

 ed to follow the advice of Dr. W. B. Niles of the Bureau of Animal 

 Industry. We are also under obligation to Dr. Niles and the 

 Bureau of Animal Industry for the necessary supplies of virulent 

 blood and immune hogs with which to start the manufacture of 

 serum. 



In view of the certainty of the results of serum inoculation, 

 which have passed beyond the experimental stage into the realm of 

 established fact, this establishment must be regarded as indispen- 

 sable to the satisfactory regulation and treatment of cholera in 

 hogs, as the disease occurs at various points throughout the state 

 and is brought to our attention. The production of serum under 

 state auspices has been generally established throughout the country 

 and meets the requirements as to uniformity of strength and re- 

 liability as to quality, etc. The manufacturing of serum should 

 receive the continued support of the state, in order that the great 

 industry of hog raising may not suffer. 



HOG CHOLERA AND ITS PREVENTIVE TREATMENT. 



HOG CHOLERA. 

 BY DR. R. E. GRAHAM. 



Hog cholera or swine fever is an infectious disease characterized by its 

 contagiousness and high death rate, attacking swine in two forms; the 

 acute and chronic types. The former is characterized by its sudden onset 

 and rapid course which terminates in death, while the latter or chronic 

 form lingers for weeks and even months and generally results in death. 

 Recovery produces a nonsusceptibility to subsequent attacks. The causa- 

 tive agent is supposed to be the same in both cases, the courses or type 

 of the disease being determined by the virulency of the organism and the 

 resisting power of the hog. The lesions of the peracute cases are not as 

 well defined as those in subacute and chronic cases, and a carcass from the 

 very acute type might not show sufficient lesions to diagnose the case 

 while in the subacute or chronic cases the intestinal lesions predominate, 



