MODE OF INFECTION AND PATHOLOGIC CHANGES 305 



through feed, bedding, harness, etc., which have been soiled with 

 the discharge from glanderous ulcerations or suppurating foci. 



Wherever, in natural infection, glanders bacilli have gained entrance 

 into the body of a susceptible animal, they multiply locally and 

 cause a cell necrosis. This is followed by an inflammatory reaction 

 with hyperemia, transudation, and emigration of leukocytes. The 

 inflammatory reaction, however, does not limit the infection but the 

 bacilli continue to multiply and the necrotic processes spread and 

 with them the inflammatory reaction. The infection is spread both 

 by direct extension from the multiplying glanders bacilli and by 

 transportation of bacilli to neighboring or more distant parts of the 

 body through the agency of leukocytes which have taken them up 

 but have not killed them. At these points they again multiply and 

 give rise to the same lesions which they produced at the original 

 place of entrance. The infection may also be spread in a glanderous 

 animal by the discharge from the lesions flowing over a mucous 

 membrane. In this manner the disease may spread from the nose to 

 the trachea, bronchi, and lungs; or, in primary pulmonary cases, the 

 mode of extension may be from the lungs outward. 



The anatomical changes which glanders produces in the skin, 

 mucous membranes, and various internal organs vary according to 

 the location and the virulency and acuteness or chronicity of the 

 process. According to Kitt, four anatomical types of lesions are 

 distinguished, namely: The glanders nodule, the glanders abscess, 

 and ulceration, the glanders induration, and the glanders infiltration. 



Nodules. The formation of the glanders nodule may be studied 

 in the nose of the horse. Following the invasion and multiplication 

 of the glanders bacillus a small, slightly elevated, grayish- white, trans- 

 parent nodule, varying in size from a small shot to a pea, is formed 

 as the result of the inflammatory cellular infiltration. In consequence 

 of the necrosis in the interior of the nodule a small abscess cavity 

 in its centre soon develops. When the necrosis extends outward far 

 enough a loss of substance occurs at the highest point and an open 

 ulcer is formed. 



Ulcers. The glanders ulcers are at first generally spherical, but 

 they become irregular, either by an irregular extension of the necrosis 

 at the periphery or by the confluence of neighboring spreading ulcers. 

 The ulceration in glanders have an excavated, eaten-out appearance. 

 They are surrounded by elevated margins and the ulcer is covered 

 by a thin, greenish-white, seropurulent discharge, sometimes slightly 

 stained with blood. If dried out, it covers the ulcer as a dirty grayish- 

 brown crust. In the skin the glanders nodules may be as large or 

 larger than a hazel nut and a distinctly palpable abscess may be felt 

 before the outer portion of the abscess wall is broken through and an 

 ulcer formed. When glanders nodules are first formed in the lungs, 

 as in the pulmonary form of the disease, they are small, grayish-white, 

 translucent nodules which somewhat resemble young tubercles. The 

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