DISEASES OF THE HOKSE. 518" 



ous other horses and mules, some of which are sure to be the bearers 

 of the germs of this or some other infectious disease, and at last it 

 succumbs. 



The period of the eruption of the last permanent teeth or the end 

 of the period of development from the colt to an adult horse, at which 

 time the animals usually have a tendency to fatten and be excessively 

 full-blooded, also seems to be a predisposing period for the contraction- 

 of this as well as of the other infectious diseases. Thoroughbred colts- 

 are very susceptible, and frequently contract strangles at a somewhat 

 earlier age than those of more humble origin. Mules and asses are- 

 much less susceptible and are bvit rarely affected. Other animals are 

 not subject to this disease, but there is a certain analogy between it 

 and distemper in dogs. After exposure to infection there is a period 

 of incubation of the disease, lasting from two to four days, during 

 which the animal enjoys its ordinary health. 



Sxjmptoms. — The horse at first is a little sluggish if used, or when* 

 placed in its stable, is somewhat dejected, paying but moderate atten- 

 tion to the various disturbing surroundings. Its appetite is somewhat 

 diminished in many cases, while in some cases the animal eats well 

 throughout. Thirst is increased, but not a great deal of water is takei> 

 at one time. If a bucket of water is placed in the manger the patient 

 will dip its nose into it and swallow a few mouthfuls, allowing some 

 of it to drip back, and then stop, to return to it in a short time. The 

 coat becomes dry and the hairs stand on end. At times the horse will 

 have chills of one or the other leg, the fore quarters, 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 ros}^ color. The pulse is quickened and the breathing 

 may be slightly accelerated. At the end of a couple of days a couf;b 

 is heard and a discharge begins to come from the nostrils. This dis- 

 charge is at first watery; it then becomes thicker, somewhat bluish va 

 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 maj^ be only a 

 catarrh of the nasal canals, or it may be from the throat, the wind- 

 pipe, or the air tube^ of the lungs, or even from the lungs themselves. 

 According to the organ affected the sj'mptoms and character of cough 

 will be similar to those of a laryngitis, bronchitis, or lung fever caused 

 by ordinary cold. 



Shortl}'^ after the discharge is seen a swelling takes place under the 

 jaw, or in the intermaxillary space. This is at first pufiy, swollen^ 

 14384—03 33 



