Extinction of Hog Cholera in Herds and Districts. As in all deadly plagues this should be a recognized governmental function to be carried out at public expense. It is a question of political economy and its neglect is subversive of prosperity not in Agriculture alone but in all public industries whose workers must subsist on the fruits of the soil. The $10,000,000 lost yearly by the farming community, is a dead loss, not to agriculture alone, but to the prosperity of the nation, the markets of which would be revived and improved by such a yearly sum expended.
The existence of the disease at any point should be reported by the stockowner or guardian, under penalty in case of failure. When the nature of the outbreak has been certified by the expert, the district should be scheduled, and the herd appraised, slaughtered and all products disposed of in such a way as to prevent any escape of infection. The carcasses may be burned, buried deeply, or boiled and rendered. The buildings, yards, utensils, fences, manure, cesspools, and infected fields should be thoroughly disinfected, or secluded from all animals for a year. The owners of the herd should be indemnified according to appraisment, and not to exceed ¾ths of the actual market value, provision being made that no award shall be made if the herd sickened within a fortnight after their arrival from another State, or in case the owner, has concealed the existence of the illness, or has otherwise deliberately or carelessly contributed to its spread.
Many minor rules and restrictions will be required to fit the general measures to individual cases and local conditions, and these require the direct supervision of an expert, and not of a mere business manager or layman.
Therapeutic Treatment. With state, county or municipal measures for the extinction of hog cholera, treatment is to be condemned, as calculated to encrease and spread the infection. But until the states can be educated out of the past wasteful system, into economical measures of extinction, the swine breeders are entitled to whatever salvage they can secure through therapeutics. For acute cases there is no hope. For the chronic a clean, dry, comfortable pen, well disinfected, and a moderate diet of varied and laxative food are essential. Wheat, bran or middlings, with corn, oat, barley or linseed meal may be allowed in form of a mash. A little green vegetable food may be added. Medicinal agents may be used to meet special indications, but when a whole herd must be treated at once, antiseptics and febrifuges have apparently proved the most generally helpful. The Bureau of Animal Industry especially recommends the following: Wood charcoal, sulphur, sodium sulphate and antimony sulphide, of each 1 lb.; sodium chloride, bicarbonate and hyposulphite, of each 2 lbs.; mix thoroughly and add to each feed in ratio with the size of the patient. In suitable cases, this is said to improve the appetite and contribute much to convalescence. Modifications will readily suggest themselves to meet individual conditions and different stages of the disease—antithermics, eliminants, calmatives. stimulants, tonics, etc.
Serum Therapy. This has been especially exploited and advocated in America by De Schweinitz of the Bureau of Animal Industry, and Dr. Peters of Lincoln, Neb. In Europe, Perroncito has prepared an antitoxin. The serum is produced in the body of the cow or other animal which is inoculated repeatedly with gradually encreasing doses of living hog cholera cultures and with solutions of the bacilli and their products, for a period of eight months, or until no reaction takes place from large doses, and the blood serum added to cultures of hog cholera bacilli causes agglutination of the latter. The serum is further tested as to its power of preserving Guinea pigs inoculated with a lethal dose of live hog cholera cultures. After separation from the blood the serum is concentrated until it reaches a standard at which 10cc. proves curative to a pig of 40 to 60 lbs. weight.
It proves most successful in animals in which the subacute or chronic form of the disease has just begun. One injection only was given to each animal. Of 1923 cases treated (1897–8) 30 per cent. died, and 70 per cent. recovered. Of 3197 in abandoned herds (checks), 81.24 per cent. were lost. (De Schweinitz.)
One drawback was found in the short period of immunity secured, the susceptibility reappearing as soon as the antitoxin had been eliminated from the body. This was met in part by using sterilized cultures (toxins) along with the serum.
Another desideratum was a speedy means of distinguishing in field work between hog cholera and swine plague, as the antitoxin of the one was not protective against the other. To meet this, serum was obtained from an animal immunized to both diseases, or a mixture was made of the sera of two animals respectively made resistant to the two affections.
De Schweinitz was very optimistic in the matter, claiming that the serum is absolutely harmless, can be used on pigs freely, and will cost but 15 cents for each animal. He estimated that of the $15,000,000 per annum lost by Hog Cholera and Swine Plague in Iowa alone, $11,000,000 can be saved at a comparatively small cost.
The method is scientifically sound in availing of the defensive products of the immunized system for imparting to the animal attacked, the power of vital resistance, and after allowing for enthusiasm, for the inevitable mistakes, when used on a large scale, of other deadly swine diseases for hog cholera, for the many accidents incident to its application by operators who are not specially trained like the employés of the Bureau, for its demand for acute and deadly outbreaks, as well as for chronic and mild ones, and taking into account that in other hands it has not fully borne out the promise made for it; yet it seems to have some measure of merit, and where no systematic attempt is made by the authorities for the extinction of the disease and its germ, it is an available resort for the owner of herds.