116 Biological Therapy 



is due largely to his experience in treating acute infections 

 in the English armies during the World War. These cases 

 were most successfully treated by the use of bacterins. In 

 championing the use of bacterins for therapeutic purposes 

 Wright states that the rule for dosage should be: ''The more 

 acute the disease the larger and the more frequent the dose.'' 

 He further states that failure to obtain satisfactory therapeu- 

 tic results in the treatment of acute infections is due to : 



1. Incorrect diagnosis and the consequent use of the 

 improper bacterins. 



2. Insufficient dosage. 



3. Improperly prepared bacterins. 



In practice bacterins are now extensively used for the 

 treatment of acute disease particularly in grade animals 

 whose limited value makes the liberal use of immune sera 

 impractical. Although in acute conditions immune sera 

 should be preferred to bacterins whenever possible, good 

 results may be expected from the latter when properly used. 

 In acute conditions the rule of Wright should be followed and 

 animals should receive full doses every day until tempera- 

 ture drops to normal and the acute symptoms subside. Such 

 results are frequently observed after the second or third 

 subcutaneous injection. 



Infectious Abortion in Cattle 



This disease for many years has constituted a serious 

 menace to the live stock industry since the losses which it 

 inflicts are not exceeded in any other disease of cattle. For 

 this reason its control offers one of the big problems of 

 veterinary medicine. 



CAUSE 



Abortion disease is due to a specific micro-organism, 

 the bacillus abortus (Bang). This organism is responsible 

 for a group of pathological changes in the uterus and pla- 

 centa resulting in a clinical syndrome of which the aborted 

 fetus is a part. Following this abortion there may be re- 

 tained placenta, metritis and sterility as well as scour and 

 pneumonia in the calves from affected cows which do not 

 abort. B. abortus may be isolated from the diseased uterus. 



