Specific and Contagious Diseases. ISI 
upon an altered condition of the blood, leading to an 
asthenic or debility of a peculiarly low type. It may be 
located at one time in a special set of organs, and during 
a succeeding attack the manifestations are removed to a 
totally distant part: thus, at one time it is wholly catarrhal, 
and in other instances it proves to be either pulmonary, 
intestinal, hepatic, or cerebro-spinal, all of which may 
suffer modification in their special characteristics under 
various circumstances. 
Causes.—Contact with diseased animals is perhaps the 
chief. The exciting causes are those which by inducing 
debility, impoverishment of the blood, &c., favour the 
attack, such as bad or insufficient food, damp, over- 
crowded, or ill-ventilated dweilings, over-feeding, want 
of exercise, &c. &c. Worms and teething also contribute 
their share in reducing the natural stamina of the system. 
As we are assured of the demonstration of a special 
disease producing bacterium of micrococcus characters, 
we may content ourselves, in the inevitable assurance of 
the contagious cause under all circumstances. 
Symptoms.—The most recent views of*the nature of 
this disease are that, primarily, it is a specific form of 
catarrh, in which the mucous membrane of the air pas- 
sages, or the upper alimentary track, as far as the stomach, 
are involved, degenerating, as already stated, into one 
or other of the forms of pneumonia, hepatic or bilious, 
enteric or intestinal, and cerebro-spinal or nervous 
disease. 
The earliest signs of disorder are dulness, lassitude, 
snuffling or slight husk, or coughing fit, at the close of 
which the animal attempts to vomit. Somewhat later he 
is found trembling, with staring coat, a fit of shivers 
ushering in a subsequent stage. The pulse and tempera- 
ture are increased, the latter rising to 104° or 105° F. 
The respiration soon becomes accelerated, and the 
mucous membranes slightly reddened, which provokes a 
watery discharge from the eyes and nostrils, and a fre- 
quent blowing of air from the latter. In a few hours the 
watery discharges become muco-purulent, or partly 
mucus and pus, the mouth is hot, and the tongue coated 
