DISEASES OF ANIMAL 



129 



may persist for a month or more and 

 in a few cases recovery may take place. 

 In chronic cases the spleen becomes 

 greatly enlarged and soft and the large 

 intestines may show hemorrhages. 



Distribution of the disease — Hog 

 cholera is distributed generally through- 

 out the central states. It has been 

 known to occur in every state of the 

 Union, as well as in Canada. In Great 

 Britain and English colonies the disease 

 is commonly known as swine fever, or 

 pig typhoid. In Germany the disease 

 is called Schweinepest and in Scandi- 

 navia Svinpest. While hog cholera 

 may appear almost anywhere in the 

 United States, there are many large 

 areas, particularly in the Rocky moun- 

 tains and Pacific coast region where 

 hog cholera almost never occurs, except 

 by reason of importing hogs from the 

 corn belt. In such localities the farmer 

 can protect himself against losses from 

 hog cholera by quarantining every hog 

 which he buys from an outside region 

 before allowing it to be placed in the 

 hog yard or to come in contact with 

 other hogs. 



There is no good evidence for directly 

 connecting hog cholera with any human 

 disease, but it most closely resembles 

 typhoid fever. The bacillus of hog 

 cholera behaves very similarly to that 

 of typhoid fever and the disease is fre- 

 qi'ently carried in water like typhoid. 

 For this reason special care should be 

 exercised in protecting the water sup- 

 ply of swine. In some outbreaks of hog 

 cholera the healthy hogs have been al- 

 lowed to eat the carcasses of dead ones, 

 thereby transmitting the disease with- 

 out fail. 



No MEDICAL TREATMENT EFFECTD7E — 



There is no satisfactory medicinal treat- 

 ment for hog cholera. Many distin- 

 guished veterinarians have worked at a 

 remedial treatment without success. 

 Nevertheless more than one hundred 

 sure-cure patent medicines have been 

 advertised for the treatment of hog 

 cholera. According to Craig and Bit- 

 ting, who have tested nearly all of these 

 remedies, very few of them remain on 

 the market for more than two or three 

 years. Perhaps the best general treat- 

 ment may be obtained from the use of a 

 mixture of 1 part chloride of potash, 

 1 part bicarbonate of soda and 2 

 parts nitrate of potash, giving a table- 

 spoonful to each hog for a dose. More- 

 over, encouraging results have been re- 



ported from the use of similar doses of 

 a mixture containing 1 pound wood 

 charcoal, 2 pounds each of sulphur, salt, 

 baking soda and hyposulphate of soda, 

 and 1 pound each of Glauber salts and 

 antimony sulphide. These remedies, 

 however, are of little avail, except in 

 mild cases. Wherever the water supply 

 is suspected of carrying the disease, it 

 is desirable to add an ounce of blue 

 vitriol to each barrel of water. In this 

 way the water is sterilized so that healthy 

 hogs may not become infected by means 

 of their drinking water. 



Means of eradication — The chief re- 

 liance in the control of hog cholera 

 must be placed on thorough quarantine, 

 disinfection of premises and the use of 

 anti-hog-cholera vaccine. The disin- 

 fection of the premises must be carried 

 out very thoroughly; otherwise it will be 

 of little avail. If the hog houses in 

 which the disease occurs are of little 

 value, it may be best to burn them up, 

 plow the ground in the hog yards and 

 plant to some cultivated crop, using a 

 fresh, clean place for hog yards. The 

 average hog pens and yards, especially 

 if the drainage is poor, and with the 

 usual amount of cracks and crevices in 

 the houses, can scarcely be disinfected 

 by any known means. The best system, 

 therefore, consists in abandoning the 

 old yards and starting again in a new 

 place, as far from the old yards as the 

 size of the farm will permit. 



Preventive measures — In the preven- 

 tion of hog cholera by means of vaccine, 

 encouraging results have been obtained 

 from time to time, but many unfavor- 

 able results were had, and this outcome 

 could not be explained on a good basis 

 until recently. The Bureau of Animal 

 Industry has found that in addition to 

 swine plague and the form of hog chol- 

 era caused by the well-known hog 

 cholera bacillus, there is another infec- 

 tious hog disease which, in its symp- 

 toms, can scarcely be distinguished 

 from hog cholera, but which is produced 

 by virus in which no baccilli can be 

 found. We appear, therefore, to have 

 three distinct and highly infectious dis- 

 eases which may afflict a herd of hogs 

 at the same time. Working on this 

 basis, a vaccine is being prepared which, 

 it is hoped, will protect hogs against 

 any one of the three forms of disease. 

 This is necessary, from a practical 

 standpoint, for the reason, as already 

 hinted, that it is a very difficult matter 

 to determine which form of the disease 



