526 
COULON AND OLIVIER. 
This state of incertitude becomes to-day still more to be re 
gretted when the contagious character of the disease is recognized 
by law, and when pecuniary indemnity is paid to owners of ani¬ 
mals that are destroyed for the interests of all. 
The official veterinarian who in some cases, for reason, wishes 
to avoid the prescribing of excessive sanitary measures, must be 
satisfied with the possibility of meeting, in isolated cases, a non- 
contagious disease, independent of sanitary regulation. 
It is important to elucidate this question and establish a posi¬ 
tive difference, especially in relation to the lesions between the 
two forms of disease. This is the object of this paper. 
Does sporadic pneumonia exist ? Pleuro-pneumonia is a spe¬ 
cific, parasitic affection, and from that, out of the ordinary nosolog¬ 
ical list, and therefore if the existence of the sporadic disease is 
denied, the lung will be the only organ of the economy which will 
have no pathological condition: an abnormal fact, which is in¬ 
creased by that other fact that its special function, its great 
vascularity, its close functional sympathies with the skin, expose 
it more than others to external influences. This exception would 
be so contrary to the laws of general pathology that reason 
refuses to accept it. 
Acute, true pneumonia exists in ruminants; a careful observa¬ 
tion of many years convinces us of it. That it is less frequent 
than in horses, we will not deny. Besides that the two species of 
animals are in different conditions of life, the respiratory appar¬ 
atus of cattle is considerably less irritable. This irritation will 
be followed more by bronchitis than by pneumonia; and again, 
the pleura resists irritation so much that this condition is seldom 
met with except in pleuro-pneumonia. 
But it is not less certain that accidental causes, that give rise 
to a congested condition of the lungs, do not remain entirely 
harmless. 
These pathogenic causes of true pneumonia act principally in 
working animals in which the respiratory apparatus, physiologi¬ 
cally excited during work, is the natural reservoir towards which 
the blood accumulates if the circulatory equilibrium is interfered 
with by a p'eripherical cooling effect. 
