INFLUENZA AND THE INFECTIOUS DISEASES OF THE HORSE. 263 
often follows exposure to cold, upon a first subject, and then by 
contagion extends to a portion or to all the animals of the same 
stable. The case is similar with brustseuche and croupal pneu¬ 
monia. In aiming to establish the similarity of these two last 
named diseases, Dicker!)off and Dr. Mendelsohn preserved the 
serosity from the lungs of six horses which had died with brust¬ 
seuche, and in two they found micrococci similar to those which 
had been found in the lungs of a man who had died with croupal 
pneumonia (de infectiose natur der pneum. Zeitsch. fur Klin. Med. 
vii.). Both of these subjects had been suffering with simple pneu¬ 
monia and dry pleurisy. 
Brustseuche may assume the form of pneumonia, of pleurisy, 
or of pleuro-pneumonia, and under each form may last for a 
period averaging from seven to eight days—a period during which 
the virulenev has become more or less established. But this is a 
«/ 
specification which is without practical importance, inasmuch as it 
cannot be accurately determined until after death. 
Brustseuche seems to have some analogy with bovine pleuro¬ 
pneumonia, similar microscopic lesions being often found in both 
diseases ; and as each may present itself as pneumonia, resembling 
croupal pneumonia, and as exudative pleurisy. These two forms 
of peripneumonia had already been observed, and it was then held 
that an animal might contract either dry or moist peripneumonia, 
according to the dryness or the moisture of the food he might 
have eaten. 
In these two diseases, again, hemorrhagic imfractuses are 
found in the lung, whose conditions varies both with individuals 
and species. For instance, in the horse, whose tissues are gener¬ 
ally finer and more easily decomposed, these small infractus soon 
become so many purulent centres. 
To resume, all the conditions referred to seem to establish 
that there is a strong analogy of brustseuche and peripneumonia. 
Each may assume the form of pneumonia (croupal) and of pleuro¬ 
pneumonia—two new diseases which, though different, from an 
anatomical point of view, yet owe their origin to the same infec¬ 
tious germs. 
(To le continued.) 
