INFECTIOUS DISEASES. 547 



susceptible of contracting the disease, and while some of these con- 

 tract it as a general constitutional malady, in others it develops as 

 only a local sore. 



In acute glanders the contagion is found in its most virulent form, 

 as is shown by the inevitable infection of susceptible animals inocu- 

 lated with the disease, while the discharge from chronic semilatent 

 glanders and farcy may at times be inoculated with a negative result ; 

 again, in acute glanders, as we have a free discharge, a much greater 

 quantity of virus-containing matter is scattered in the neighborhood 

 of an infected horse to serve as a contagion to others than is found 

 in the small amount of discharge of the chronic cases. 



The chances of contagion are much greater when sound horses, 

 asses, or mules are placed in the immediate neighborhood of glan- 

 dered horses, drink from the same bucket, stand in the next stall, or 

 work in the same wagon, or are fed from feed boxes or mangers 

 which have been impregnated by the saliva and soiled by the dis- 

 charge of sick animals. Transmission occurs by direct contact of 

 the discharges of a glandered animal with the tissues of a sound one, 

 either on the exterior, when swallowed mixed with feed into the 

 digestive tract, or when dried and inhaled as dust. 



The stable attendants serve as one of the most common carriers of 

 the virus. Dried or fresh discharges are collected from the infected 

 animals in cleaning, harnessing, feeding, and by means of the hands, 

 clothing, the teeth of the currycomb, the sponge, the bridle, and the 

 halter, and are thus carried to other animals. 



An animal affected with chronic glanders in a latent form is moved 

 from one part of the stable to another, or works hitched with one 

 horse and then with another, and may be an active agent in the 

 spreading of the disease without the cause being recognized. 



Glanders is found frequently in the most insidious forms, and we 

 recognize that it can exist without being apparent; that is, it may 

 affect a horse for a long period without showing any symptoms that 

 will allow even the most experienced veterinarian to make a diag- 

 nosis. An old gray mare belonging to a tavern keeper was reserved 

 for family use with good care and light work for a period of eight 

 years, during which time other horses in the tavern stable were from 

 time to time affected with glanders without an apparent cause. The 

 mare, whose only trouble was an apparent attack of heaves, was sold 

 to a huckster who placed her at hard work. Want of feed and over- 

 work and exposure rapidly developed a case of acute glanders, from 

 which the animal died, and at the autopsy were found the lesions of 

 an acute pneumonia of glanders grafted on chronic lesions, consisting 

 of old nodules which had undoubtedly existed for years. 



In a case that once came under the care of the writer, a coach horse 

 was examined for soundness and passed as sound by a prominent 



