INFECTIOUS DISEASES. 529 
or hind quarters, or in severe cases of the whole body, with trembling 
of the muscles and dryness of the skin. 
If the eyes and mouth are examined the membranes are found red- 
dened to a bright rosy color. The pulse is quickened and the breath- 
ing may be slightly accelerated. At the end of two days a cough 
is heard and a discharge begins to come from the nostrils. This dis- 
charge is at first watery; it then becomes thicker, somewhat bluish in 
color, and sticky, and finally it assumes the yellowish color of matter 
and increases greatly in quantity. 
At the outset the colt may sneeze occasionally and a cough is heard. 
The cough is at first repeated and harsh, but soon becomes softer and 
moist as the discharge increases. Again, the cough varies according 
to the source of the discharge, for in light cases this may be only a 
catarrh of the nasal canals, or it may be from the throat, the wind- 
pipe, or the air tubes of the lungs, or even from the lungs themselves, 
According to the organ affected the symptoms and character of cough 
are similar to those of a laryngitis, bronchitis, or lung fever caused 
by ordinary cold. 
Shortly after the discharge is seen a swelling takes place under the 
jaw, or in the intermaxillary space. This is at first puffy, somewhat 
hot and tender, and finally becomes distinctly so, and an abscess is 
felt, or having broken itself the discharge is seen dripping from a 
small opening. When the discharge from the nostrils has fully de- 
veloped the fever usually disappears and the animal regains its ap- 
petite, unless the swelling is sufficient to interfere with the function 
of the throat, causing pain on any attempt to swallow. At the end 
of four or six days the discharge lessens, the soreness around the 
throat diminishes, the horse regains its appetite, and in two weeks has 
regained its usual condition. Old and strong horses may have the 
disease in so light a form that the fever is not noticeable; they may 
continue to eat and perform their ordinary work as usual and no 
symptom may be seen beyond a slight discharge from the nose and a 
rare cough, which is not sufficient to worry any but the most particu- 
lar owner. But, on the other hand, the disease may assume a malig- 
nant form or become complicated so as to become a most serious 
disease, and even prove fatal in many cases. Inflammation of the 
farynx and bronchi, if excessive, produce violent, harsh coughing, 
which may almost asphyxiate the animal. The large amount of dis- 
charge may be mixed with air by the difficult breathing, and the 
nostrils, the front of the animal, manger, and surrounding objects 
become covered with a white foam. The inflammation may be in the 
lung itself (lobular pneumonia) and cause the animal to breathe 
heavily, heave at the flanks, and show great distress. In this condi- 
tion marked symptoms of fever are seen, the appetite is lost, the coat 
36444°—16—_34 
