Pathogenesis. 687 



rarely found in the blood of diseased horses (as a rule only during 

 a brief period immediately after infection or in the acute form of 

 the disease) while in some experiment animals, especially cats and 

 guinea pigs this is much more frequently the case. Bonome, however,' 

 has demonstrated that intrauterine infection may occur not only as 

 a result of hemorrhage but through the intact placenta as well. The 

 extra-uterine disease of the horse has as yet never been demonstrated 

 positively to be the result of intrauterine infection. 



Pathogenesis. The discovery that the lesions of the disease, 

 in clinically healthy appearing animals that have been killed 

 on account of positive reaction to the mallein test, are found 

 almost exclusively in the internal organs, especially the lungs, 

 but also the liver and spleen (sometimes only in the latter) 

 while the nasal mucous membranes are hardly ever affected 

 until the morbid processes in the internal organs have become 

 quite advanced, point to the conclusion that the nostrils are 

 usually secondarily infected or are attacked simultaneously 

 with the internal organs. After Renault (1851) had success- 

 fully produced infection by feeding infected nasal secretions, 

 Nocard demonstrated that horses could be infected with food 

 or water that had been contaminated with only slight quantities 

 of infected secretions and that the intestinal mucous membranes 

 remained intact while lesions of the disease in the form of small 

 translucent "tubercles" were found in the lungs, liver and 

 spleen. Following this the disease continued in its usual chronic 

 character and gradually spread to other organs. Nocard 's 

 view in regard to the intestinal origin of glanders has been 

 fully confirmed by MacFadyean, Biegler, Bonome, Hutyra and 

 others. The results of Schuetz's experiments are also in har- 

 mony with these conclusions in so far as they showed that 

 the feeding of large masses of virus resulted within a short 

 time in extensive affection of the lungs. The possibility of in- 

 testinal infection is further supported by those post-iiiortem 

 observations in which lesions of glanders are noted in the 

 posterior sections of the small intestines and in the cecum; 

 finally also by the observation that carnivora in_ zoological 

 gardens usually become infected from the ingestion of the 

 organs of glandered horses. 



Nocard fed virulent cultures mixed with turnip leaves, or bread, 

 or drinking water to 20 horses, asses and mules that had had water 

 withheld from them for some time and then gave them free access to 

 all the water they would take. All of these animals reacted to mallein 

 within three to eight days and in all of them small hyaline nodules 

 or large cheesy foci developed in the lungs; in some animals the sub- 

 maxillary lymph glands, the epiglottis, the turbinated bones and the 

 nasal septum also developed glanderous lesions (some of them in 8 

 days). Schu6tz administered large masses of cultures enclosed in 

 gelatin capsules to three horses this was followed within 11 to 13 days 

 by serious affection of the lymph glands and of the lacteals of the 



