SWINE PLAGUE 51 
The effect of swine-plague bacteria on rabbits. In 1894, Smith 
and Moore described the effect of swine-plague bacteria on rabbits 
and also the effect of resistance on the part of the rabbit on the form 
of the resulting lesions. 
Among the forms of disease observed after the subcutaneous inocu- 
lation of rabbits with swine-plague bacteria from different sources 
(epizoétics) were bacteriemia, - peritonitis, pleuritis (usually with 
pericarditis), pleuritis (usually with pericarditis and peritonitis) and 
local lesion only. 
In bacteriemia, death ensues within eighteen or twenty-four hours. The local lesion 
produced at the seat of inoculation is slight. Bacteria are abundant in the parenchyma 
(blood vessels) of the various organs. In the form characterized by peritonitis death 
occurs in three to seven days. The local lesion, which in all these forms of diseases 
increases in extent with the prolongation of the life of the animal, is here characterized 
by more or less suppurative infiltration of the skin and the subcutis. The peritonitis 
in its earlier stages is characterized by punctiform hemorrhages on the cecum and a 
fibrinous or cellular exudate. It always contains immense numbers of bacteria. When 
pleuritis is also present the exudate usually involves the pericardium as well. It 
varies in amount according to the duration of the disease and is essentially the same 
as the peritoneal exudate. 
The form characterized by pleuritis and pericarditis without peritonitis is interesting 
in so far as the seat of inoculation does not explain the localization, for, in every case, 
the inoculation was made in the region of the abdomen. The lungs may become 
hepatized secondarily through invasion from the pleura if the animal lives long enough. 
Lastly, the form of disease in which the only localization is a very extensive sup- 
purative infiltration associated with hemorrhage and edema of the subcutaneous tissue 
is not common. 
Period of Incubation. In artifically produced cases it is very short, 
the symptoms appearing in from 1 to 2 days. In natural infections it 
is also believed to be short. 
Symptoms. The peculiarities of swine render it exceedingly 
difficult to obtain evidence on physical examination of lung disease or 
general infections distinctive of swine plague. Sometimes this affec- 
tion runs a very rapid course, the animal dying of bacteriemia. 
Usually it is more protracted, lasting from a few days to one or two 
weeks. There is a rise of temperature. As it advances the pigs 
become weak. In its very acute septicemic form the temperature 
is high and the duration of the disease is very short. Animals affected 
with the more chronic form eat very little or refuse food altogether. 
They cough considerably, especially when forced torun. The back is 
usually arched and the groins sunken. The whites of the eyes are 
