DISEASES OF SWINE AND OTHER ANIMALS. 409 
a serious obstacle to all attempts to stamp it out. In most of the plagues of animals, 
and notably in lung fever, in aphthous fever, and in rinderpest out of its native 
home, the rise of the body temperature precedes all outward manifestations of the dis- 
ease. In these affections the indications of the thermometer alone enable us to sep- 
arate the sick and healthy before the disease has attained toa stage of material danger 
to their fellows. . But in the pig fever the earliest symptoms will vary according to 
the vagaries of the poison and its primary seat of election. Perhaps the most common 
initial symptom is the enlargement of the inguinal glands, but it may be some derange- 
ment of the digestive organs, or it may be the elevation of the body temperature, or it 
may be the appearance of red spots or blotches on the skin, or finally the poison may 
be operating in the system in the absence of all external manifestations. It is notice- 
able that since the access of extremely cold weather the cutaneous discoloration has 
been much less extensive than during the warmer season. Even when the tempera- 
ture has been abnormally raised it will rise and fall in such an irregular manner that 
no single observation will be always successful in detecting the disease. To detect 
such cases the investigation must be conducted from day to day, and in view of all 
possible manifestations of the disease, to be successful. Then again the temperature, 
even in health, varies widely in different swine and under different conditions of life, 
so that a knowledge of the body heat of the individual in the existing environment 
is essential to the drawing of sound deductions from thermometric indications, 
INFECTION OF OTHER ANIMALS THAN SWINE. 
I consider the most important part of my researches to be that which demonstrates 
the susceptibility of other animals than swine to the fever we are investigating. Dr. 
Kline of London, England, claimed, nearly a year ago, that he had conveyed the dis- 
ease “‘ with difficulty” to rabbits, Guinea-pigs, and mice, but he gives no hint as to 
whether he had subjected the question to the crucial test of reinoculation from these 
animals back upon the pig. This test it seemed very important to apply, so that the 
_ identity or otherwise of the two diseases might be determined. I have accordingly in- 
stituted experiments on a rabbit, two sheep, a rat, and a puppy, the three former of 
which have turned out successfully. 
INFECTION OF A RABBIT FROM A SICK PIG, 
After two inoculatious with questionable results, made with the blood of sick pigs, 
in which microzymes had been observed, a rabbit was once more inoculated, this time 
with the pleural effusion of a pig that had died during the previous night, and in 
which were numerous attively moving bacteria. Next day the rabbit was very fever- 
ish and ill, and continued so for twenty-two days, when it was killed and showed 
lesions in many respects resembling those of the sick pigs. The blood of the sick rab- 
bit contained active microzymes like those of the pig. 
SUCCESSFUL INOCULATIONS FROM THE SICK RABBIT. 
On the fourth day of sickness the blood of the rabbit containing bacteria was inocu- 
lated on a healthy pig, but for fifteen days the pig showed no signs of illness. It was 
then reinoculated, but this time with the discharge of an open sore which had formed 
over an engorgement in the groin of arabbit. IIness set in on the third day and 
continued for ten days, when the pig was destroyed and found to present the lesions 
of the fever in a moderate degree. 
A second pig, inoculated with the frozen matter which had been taken from +he . 
open sore in the rabbit’s groin, sickened on the thirteenth day and remained ili for 
six days, when an imminent death was anticipated by destroying the anirial, Dur- 
ing lite and after death it presented the phenomena of the plague in a very violer.t form. 
Jt can no longer be doubted, therefore, that the rabbit is itself a victim of this disease, 
and that the poison can bereproduced and multiplied in the body of this rodent and con- 
veyed back with undiminished virulence to the pig. We may follow Dr. Kline in 
according a similar sad capacity to the other rodents, mice and Guinea-pigs. The 
rabbit, and still more the mouse, is a frequent visitant of the hog-vens and yards, 
where it eats from the same feeding-troughs with the pig, hides under the same litter, 
and runs constant risk of infection. Once infected they may ¢urry the disease as 
widely as their wild wanderings may lead them, and communicaté it to other herds at 
a considerable distance. Their weakness and inability to escays,in severe attacks of 
the disease, will make them an easy prey to the omnivorous og, and thus sick and 
dead alike will be devoured by the doomed swine. 
PROBABLE SUSCEPTIBILITY OF OTHER F.ODENTS. 
The infection of these rodents creates the strongest presumption that other genera 
of the same family may also contract the disease, and (y virtue of an even closer rela- 
