TREATMENT OF SWJNE DISEASES. 
857 
treatment to raise the horse’s immunity to such a degree that 
the serum is valuable for the treatment of hogs. Some horses 
will never yield good serum ; others may die from the effects of 
the virus before they have reached the proper stage of immu¬ 
nity. With skillful management, however, a large proportion of 
the horses can be made to yield a good serum after three to five 
months’ treatment. 
After the horse has been given a proper degree of immunity 
blood may be drawn from it every five or six weeks ; but it will 
not continue to yield a high quality of serum unless the inocu¬ 
lation with large doses of virus is repeated from time to time. 
It is thus seen that the production of serum is a difficult 
matter, and one which requires the constant services of experts. 
The virus for the inoculation of the horse must be properly pre¬ 
pared and must be pure. This demands the skill of an experi¬ 
enced bacteriologist. The virus must be administered in proper 
doses and with proper intervals, taking into consideration the con¬ 
dition of the horse to be operated upon. This can only be deter¬ 
mined by the experience and judgment of the operator. Finally 
the blood must be drawn without permanently injuring the 
veins, and without allowing it to become contaiminated witn 
atmospheric or other germs. 
If the horse has been treated with hog-cholera virus, its 
serum will be efficacious for the treatment and prevention of 
hog-cholera, but will have no effect upon swine plague, and 
vice versa. Now, as we are liable to encounter either one or the 
other of these two diseases, and frequently find both diseases in 
the same herd and affecting the same animal, and as it is diffi¬ 
cult to distinguish with certainty between these diseases with¬ 
out resorting to tedious bacteriological methods, it is essential 
that any remedy shall have a favorable effect upon both diseases. 
To accomplish this object we have used a mixed serum—that 
is, a mixture of serum from a horse made immune to hog- 
cholera with other serum from a horse made immune to swine 
plague. Or a single horse may be made immune to both di¬ 
seases and will then furnish a serum curative for both diseases. 
The serum obtained in this way, if carefully bottled for use, 
will keep for a considerable time. The dose to be used varies 
from two to five drams, according to the size of the hog. It is 
injected under the skin with a hypodermic syringe, and one 
dose is all that is ordinarily given. 
As has already been stated, this serum produces immunity 
in well hoo^s and has a curative effect on those which are sick. 
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