Lesions 



711 



nary medicine, the reaction following its injection into glandered 

 animals being similar to that caused by the injection of tuberculin 

 into tuberculous animals. The preparation of mallein is simple. 

 Cultures of the glanders bacillus are grown in glycerin bouillon for 

 several weeks and killed by heat. The culture is then filtered 

 through porcelain, to remove the dead bacteria, and evaporated to 

 one-tenth of its volume. Before use the mallein is diluted with 

 nine times its volume of 0.5 per cent, aqueous carbolic acid solution. 

 The dose for diagnostic purposes is 0.25 cc. for the horse. It has 

 also been prepared from potato cultures, which are said to yield 

 a stronger product. The agent is employed exactly like tuberculin, 

 the temperature being taken before and after its hypodermic in- 

 jection. A febrile reaction of more than i.s°C. is said to beindicative 

 of the disease. 



Pathogenesis. — ^That the bacillus is the cause of glanders there is 

 no room to doubt, as Loffler and Schiitz have succeeded, by the 

 inoculation of horses and asses, in producing the well-known disease. 



The goat, cat, hog, field-mouse, wood-mouse, marmot, rabbit, 

 guinea-pig, and hedgehog all appear to be susceptible. Cattle, 

 house-mice, white mice, rats, and birds are immune. 



Infection may take place through the mucous membranes of the 

 nose, mouth, or alimentary tract, and apparently without preexisting 

 demonstrable lesions. 



The disease assumes either an acute form, characterized by de- 

 structive necrosis and ulceration of the mucous membranes with 

 fever and prostration, terminating in pneumonia, or, as is more 

 frequent, a chronic form ("farcy"), in which the lesions of the 

 mucous membranes are less destructive and in which there is a 

 generalized distribution of the micro-organisms throughout the body, 

 with resulting more or less widespread nodular formations (farcy- 

 buds) in the skin. The acute form is quickly fatal, death some- 

 times coming on in from four to six weeks; the chronic form may last 

 for several years and end in complete recovery. 



Lesions. — When stained in sections of tissue the bacilli are found 

 in small inflammatory areas. These nodules can be seen with the 

 naked eye scattered through the liver,' kidney, and spleen of animals 

 dead of experimental glanders. They consist principally of leuko- 

 cytes, but also contain numerous epithelioid cells. As is the case 

 with tubercles, the centers of the nodules are prone to necrotic 

 changes, but the cells show marked karyorrhexis, and the tendency 

 is more toward coUiquation than caseation. The typical ulcerations 

 depend upon retrogressive changes occurring upon mucous surfaces, 

 the breaking down of the nodules permitting the softened material 

 to escape. At times the lesions heal with the formation of stellate 

 scars. 



Baumgarten* regarded the histologic lesions of glanders as much 



* " Pathologische Mykologie," Braunschweig, 1890. 



