PNEUMONIA IN THE HORSE. 
249 
the disease. These are every-day observations, which may be 
made by any practitioner. 
According to bacteriology, pneumonia can be divided into 
three kinds : 
(i) In which the kokko bacilli work alone and are easilv 
found. 
(2) The effect of the streptococci is already significant 
but not yet general. It is difficult to find the specific microbe. 
# ( 3 ) ^ le streptococci has penetrated the blood and tissues. 
It is impossible to find the specific microbe. 
Diseases produced by experimental inoculations of kokko 
bacilli have often terminated in streptococci pneumonia, which 
is done by placing a small collodion sack containing kokko 
bacilli into the abdomen of a rabbit ; the result is a streptococci 
pneumonia. This experiment in horses will be performed in a 
short while. 
After all this, one may be disposed to remark that pneu¬ 
monia is typhoid fever of the horse, with localization in the or¬ 
gans of the thoiacic cavity, but this would not be correct, as all 
the characteristics of typhoid fever are not present. 
One should talk of it as pasteurella. To this new apprehen¬ 
sion one may oppose that typhus of the horse is far more 
infectious than the pneumonias. Really all the pneumonias are 
•contagious, and if this is less than in the typhoid form it is due , 
to the higher virulency of the microbes in the latter. Often one 
may notice the enzootic form of pneumonia when in a stable, 
most of the animals becoming affected. It may be that the strep¬ 
tococci obtain higher pathogenic properties by passing through 
different passages of the animal’s body. 
The specific kokko bacilli produce only a relative and not 
an absolute immunity. Horses may become affected several 
tunes from pneumonia. The fact that it is possible to produce 
immunity through weakened cultures is sure. Tigniere did 
not have the opportunity yet to verify the practical inocula¬ 
tions as he succeeded with it in the pasteurella of cattle. 
Most of the experiments were done by the veterinarian 
