6 The Bulletin 



also in the excretions from such hogs, particularly in the urine. It has 

 been demonstrated time and again that the disease can be produced by 

 injecting the blood or urine of a sick hog into a well one. 



The germ, which is in the blood or urine, is either so small or of Such 

 stinicture that it cannot be seen with the strongest microscope now avail- 

 able. Therefore, the germ of hog cholera is classified with the "invisible 

 micro-organisms." In this respect it resembles manj^ other infectious 

 diseases of animals and men. \ 



The Predisposing Cause 



The specific cause of hog cholera is the minute micro-organism just 

 referred to, yet there are a number of things that tend to make the hog 

 more susceptible. In fact anything which tends to lower the vitality of 

 the animal may be regarded as predisposing causes. The following may 

 be mentioned : insanitary condition of the hog lots, filthy drinking and 

 feeding troughs, improper feed and feeding, damp or cold sleeping 

 places, etc. 



It is to be understood that insanitary conditions, improper feeding, and, 

 in general, bad surroundings, cannot, within themselves, produce a case of 

 hog cholera, as the disease is caused by a specific organism which must 

 gain entrance into the body before a case of hog cholera is produced. 

 But hogs of low vitality become comparatively easy victims of any dis- 

 ease-producing germs when exposed. 



Period of Incubation 



The period of incubation is the number of days between contracting 

 the germ causing hog cholera, and the manifestation of the first symp- 

 toms or evidence of sickness. This time ranges from four to twenty-one 

 days, dependiing on the susceptibility of the individual hog and the 

 vimlence of the infection. 



An acute form of hog cholera indicates a virulent form of infection, 

 while a slow or chronic form of hog cholera indicates an infection weak 

 in virulency. 



SYMPTOMS 



A post-mortem and anti-mortem study of hog cholera will show a 

 greater variety of symptoms than any other disease afi'ecting hogs. 

 For this reason, it is often hard for the farmer who has not had special 

 training along this line to detect the first sick hog in his herd, and 

 often a large per cent of his hogs are sick before he even suspects they 

 are sick. Then not being able to detect the nature of the disease he 

 does nothing until most of his hogs are sick and the first one to show 

 any signs of being sick are beginning to die, when it is too late to do 

 anything. So far, wc know nothing that will cure an advanced case of 

 hog cholera. Then, again, we see in some herds one or two hogs that 

 contract a mild form of the disease and are ofF feed for a few days, but 



