306 ACUTE GENERAL INFECTIOUS DISEASES 



after year new outbreaks pf the disease. It is possible for this 

 dysentery to develop in a stable without being imported. 

 This is probably due to colon bacilli, which are living as 

 saprophytes on the premises, assuming a virulent form once 

 introduced into the bodies of calves with lowered resistance 

 (bad sanitation, improper feeding). The infesting germs may 

 enter the body: (a) via navel cord or (b) via digestive tract. 

 Calves are often attacked before they have suckled their 

 dams. An intra-uterine infection seems to be proved by the 

 fact that an injection of a virulent culture of the colon bacillus 

 into the jugular vein of a pregnant cow, was followed in eight 

 days by the birth of a calf with the disease. Removing the 

 pregnant dam to a non-infected place does not always protect 

 her young from infection. Calves which have not yet sucked 

 seem most predisposed; and resistance against infection in- 

 creases as the calf becomes better nourished through its 

 natural food. After eight days of extra-uterine life the danger 

 of infection is passed. 



Symptoms. — The symptoms appear in from a few hours to 

 three days after birth, rarely later. The principal indication 

 of the disease is diarrhea. The liquid feces are at first expelled 

 with considerable straining (tenesmus), a strong stream of 

 yellow-colored, fetid discharge being shot from the rectum. 

 Later the evacuations become whiter in color and thinner in 

 consistency, often mixed with blood and food. The patient 

 rapidly grows weak, languid, refuses to suck, the eyes become 

 retracted and dull, the anus relaxes, causing fecal incon- 

 tinence, the hair coat becomes erect, and finally under symp- 

 toms of coma death occurs. The temperature is somewhat 

 elevated (105° F.) in the early stages, but later may become 

 subnormal. There is also dypsnea and rapid pulse. 



Diagnosis. — Usually easy. This infectious dysentery is dif- 

 ferentiated from sporadic diarrhea of young animals in that it 

 affects only those less than one week old, induces a fetid, 

 exhaustive, and rapidly fatal diarrhea and assumes an 

 enzootic form. In acute gastro-intestinal catarrh ("scours") 

 due to dietetic irregularities older sucklings are attacked, the 

 general symptoms are much less pronounced, and the feces 

 are thicker, yellower, and less fetid. 



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