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 suflScient 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 suflScient 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 

 larynx 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 



