396 DISEASES OF SWINE 



sick. If the serum is of proper quality, and has been properly- 

 tested out at the serum plant before being shipped out, this sick- 

 ness should only be temporary in nature. 



There is a slight elevation of temperature, the animal may be a 

 little off feed, and somewhat droopy. That is about all that will be 

 noticed. This is not seen in all of the animals by any means. It 

 may not be noticeable in any of them. In other herds one or two, 

 or even perhaps a half-dozen, may show these signs of a strong 

 attack by the virus of the disease. 



These cases are to be explained by the fact that these animals 

 are very easily affected by the germs of cholera, and, even when 

 protected by serum, are inclined to show some effects from the 

 attack of the virus. It is these animals that get sick first at an 

 outbreak of the disease in a herd, and are dead almost before the 

 owner realizes that there is anythmg wrong with them. 



Question of Spreading Infection. — There are some very careful 

 investigators with hog-cholera who are opposed to this double 

 method of treatment. They base their objections on the ground 

 that these double-treated hogs do actually go through a mild attack 

 of the disease, and that the manure, urine, and other discharges 

 contain the virus of the disease. They claim that these discharges 

 cause an infection of the premises and prove the source of an out- 

 break of the disease the following year. In this manner they argue 

 that where we only had a few infected feed lots this year, we will 

 next year have a large number of them. This will mean a wider 

 scattering of the disease and more cholera every summer than we 

 had the year before. 



Their point, however, I believe to be poorly taken. I know of 

 no case where this has ever been proved to be the case. It is very 

 doubtful if the discharges of these animals which receive the double 

 method of treatment are really capable of producing the disease or 

 infecting the feed lots. Especially is this true in those cases in 

 which the animals do not show any bad effects following the use of 

 the treatment. It is barely possible that where one or more ani- 

 mals show symptoms of a mild attack of the disease after the 

 giving of the double treatment there might be infection of the 

 feed lots. 



Several experiments have been made along this line, and I 



