494 



equally unclean, where it meets many opportunities of infection. If it 

 escapes so far, it reaches the time for heavier work and daily contact 

 on the streets of towns or large cities, with numerous 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 erui)tion 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- 

 blood- d, also seems to be a predisposing periotl 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 sus- 

 ceptible and are but 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. 



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

 jjlaced 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 taken 

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

 patient, it will dip its nose into it and swallow a few mouthfuls, allow- 

 ing 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, dryness of the skin, and its hairs standing on end. 



If the eyes and mouth are examined the membranes are found red- 

 dened to a bright rosy color. The pulse is quickened and the breathing 

 may be slightly accelerated. At the end of a couple of days a cough is 

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

 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 windpipe, 

 or the air-tubes of the lungs, or even from the lungs themselves. Ac- 

 cording to the organ affected the symptoms and character of cough 

 will be 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 



