758 MICROBIOLOGY OF DISEASES OF MAN AND DOMESTIC ANIMALS 



The bacteria are present in the faeces, intestinal mucosa, and sub- 

 mucosa, most frequently in the small intestines. The large intestines 

 may be involved later. 



This microorganism produces chronic, inflammatory changes of the 

 intestinal mucous membrane, the whole intestinal wall becoming 

 greatly thickened. 



This bacterium resembles closely avian tubercle bacteria, but may 

 be distinguished by the fact that the avian tubercle bacterium is rather 

 easily grown on artificial media. This organism does not have the 

 same pathogenic peculiarities as the avian tubercle bacterium. It 

 seems well demonstrated that many cases of chronic bacterial enteritis 

 do probably react to avian tuberculin; but this does not prove identity. 



So far as known the bacterium is eliminated in the manure of 

 affected cattle and disseminated in this way. Wider dissemination is 

 made by diseased animals moving from place to place. 



The most important considerations in controlhng this disease are 

 careful disposition of contaminated manure and' isolation of suspected 

 animals. The manure should be used only where it can not serve to 

 spread disease to other cattle. Sick animals should^e carefully isolated 

 and premises thoroughly disinfected. 



Contagious Abortion of Domestic Animals* 

 Bacterium aborttis 



The premature discharge of the products of conception from the 

 uterus is a not infrequent occurrence among domestic animals, and 

 doubtless various factors may from time to time operate in its causation. 

 Injury, excessive fermentable food, or poisonous food may at times 

 produce this result. For a long time, however, practical husbandmen 

 have recognized an epizootic form or a contagious abortion, a definite 

 transmissible disease, of which the loss of the foetus is the most promi- 

 nent characteristic. This disease appears to be generally distributed 

 in aU agricultural communities. Cows, especially, are affected, but a 

 somewhat similar if not identical disease also occurs in other domestic 

 animals. 



In 1897 Bernhard Bang discovered in the uterine exudate of a cow, 

 slaughtered during an attack of this disease before the abortion had " 



* Prepared by W. J. MacNeal. 



