426 TWENTY-SECOND ANNUAL YEAR BOOK— PART V 



ney, intestine, bladder, and lymph glands, but there are cases of death 

 from cholera virus with little change in the carcass so far as the naked 

 eye can detect. 



In this connection the history of the disease is of vast importance and 

 should always be given due weight in arriving at a diagnosis of the nature 

 of the disease to contend with. Remember that when a disease seems 

 epidemic in a community and hogs are actually dying from it, there is 

 nine chances in ten that it is hog cholera, for this infection is responsible 

 for 90 per cent of the hogs we lose from contagious diseases. Proceed 

 on the plan that it is safer to assume that you have cholera to deal with 

 if you have sick hogs and that it is your task to prove that it is not 

 cholera rather than the reverse attitude which so many assume. Surely 

 it is not necessary to again emphasize that we can control hog cholera, 

 but it is pertinent to say that it is indeed regretable after science and ex- 

 perience has discovered and perfected a means of protecting swine against 

 this age-old scourge that is really responsible for most of oiir hog losses 

 the country should be still suffering the heavy losses it endures, yet so 

 cheaply avoided. 



When cholera is epidemic as it is today and has been for several months 

 over a large area of the corn belt, the hog owner should remember that 

 it is almost best to insure the herd in advance by vaccinating them while 

 healthy, for results are not nearly so good in using anti-hog cholera serum 

 as a curative as it is to make thrifty hogs immune to the infection of 

 cholera. 



II. Swine Plague 



This is mentioned more than it used to be, and we no doubt have cases 

 of swine plague to deal with in Iowa at times. This disease has been 

 recognized for years both in Europe and America. 



It produces its lesions in the lung tissues and in lymphatic glands. The 

 onset is usually sudden and the animal seems quite prostrate, but the 

 death loss is exceedingly low and recovery as rapid and complete as the 

 start was sudden. Actual deaths from swine plague seldom exceed 5 

 per cent of the herd under good care and management. Several seasons 

 of observation impel me to say that no one as yet has demonstrated 

 either a cure or prevention for this disease. In spite of this fact, how- 

 ever, there has been a wide use of so-called "mixed infection" bacterin, 

 swine plague vaccine, and hemorrhagic septicemia vaccine for swine in 

 our hog yards the past few seasons. This would not be so lamentable 

 were it not for the fact that in scores of cases sick herds have been as- 

 sumed to have swine plague, flu or mixed infection and as a result re- 

 ceived one to three treatments with these worthless bacterins when the 

 filterable virus of hog cholera was at the root of the trouble and anti- 

 hog-cholera serum used early would have saved most of the herd from 

 death. Good money was wasted for worthless medication and hogs were 

 permitted to die that could have been saved by intelligent diagnosis of 

 the existing disease. 



From September to April simple pneumonia, lung fever, congestion of 

 the lungs, or whatever one wishes to term it, is a frequent cause of trouble 

 among swine. In most cases it is because of overcrowded hog houses, 



