Congenital Infections of Calves 653 



Calf dysentery has long been a fruitful field of contro- 

 versy as to cause. Its intelligent study has been held back 

 largely by false theories as to its nature. Many have held 

 that it was due wholly and directly to improper feeding, 

 and the claim has been so often repeated that it has ac- 

 quired the weight of a fact. Some also taught that it was 

 due entirely to navel infection, and this, too, became a com- 

 mon belief. All prophylactic and curative efforts based upon 

 either of these beliefs came to naught, and when these er- 

 roneous theories had failed the truth largely went unsought. 

 The theories mentioned above belittled the significance of 

 dysentery in calves. If merely a matter of feeding, any 

 person of moderate intelligence should readily control it. 

 If due wholly to navel infection, ordinary cleanliness would 

 obviate the difficulty. It was therefore technically an un- 

 important affair from the standpoint of the pathologist and 

 a virtually hopeless scourge from the viewpoint of the 

 breeder whose calves were persistently dying. 



Calf dysentery is slowly becoming recognized as one of 

 the links in an endless chain of infection invading the geni- 

 tal organs of breeding cattle of both sexes, passing over 

 from the uterus of the pregnant cow to the digestive tract 

 of the embryo within her uterus, and, under favorable en- 

 vironment, capable of causing retained afterbirth in the 

 mother, or serious or fatal sepsis, dysentery and pneu- 

 monia in the calf, or of escaping from the digestive 

 tract to invade permanently other systems or organs. 

 Under this broader conception, the dysentery of calves 

 becomes an integral part of one of the most important 

 diseases among domestic animals. The term is commonly 

 applied to a diarrhea or dysentery occurring in calves 

 a few hours to a few days after birth. Some writers 

 limit the period to the interval between a few hours to three 

 or four days after birth. Diarrhea occurring in calves at 

 other times is otherwise designated, but the line of demarca- 

 tion is not clear and the limitation to such a period as indi- 

 cated is purely arbitrary. 



Diarrhea is common in the fetus. Physiologically, as soon 



