EQUINE GLANDERS 361 



to be relatively insusceptible, and that infection may be 

 possible by inhalation. In the horse glanders is readily 

 transmissible experimentally both by ingestion and by 

 inoculation, and ingestion is probably the common mode 

 of infection naturally, infection by inhalation occasionally 

 occurring. Even when glanders bacilli are administered 

 experimentally by the mouth in the horse, the lesions may 

 be most prominent in, or even be confined to, the lungs. 

 In the horse, the disease has periods of epidemic preva- 

 lence, and is particularly frequent in London. In 1902 

 there were 2,499 well-developed equine cases in Great 

 Britain, nearly 90 per cent, of which occurred in the 

 Metropolitan area, but there are also numerous others in 

 which it is latent. Since 1908, the disease has decreased, 

 for in 1914 there were 269, and in 1918 only 98, equine 

 cases. Guinea-pigs and field mice are highly susceptible 

 to the disease, which may also be contracted by some of 

 the Carnivora, such as the cat, lion, and tiger, by inocula- 

 tion or by feeding on diseased carcases. The rabbit, sheep, 

 and dog are but slightly susceptible, while cattle, swine, 

 and house mice are stated to be immune. Shattock l 

 found that the white mouse is somewhat susceptible, and 

 suggests that probably the house mouse is similarly so. 



In the horse the most constant seat of glanders lesions 

 is the lung, and McFadyean states that no case of glanders 

 with lesions elsewhere than in the lungs, and with these 

 organs unaffected, has ever been recorded. In nearly 

 every case of farcy, also, nodules are present in the lungs. 

 The lung lesions have the form of rounded, firm, or shotty, 

 nodules. The number present is variable, rarely less than 

 a dozen ; exceptionally there are hundreds, fairly evenly 

 distributed throughout the lung tissue. The nodule com- 

 mences as a collection of polymorphonuclear leucocytes, 

 around which a zone of congestion is present. Later, 



1 Trans. Path. Soc. Lond., vol. lix, 1898, p. 333. 



