THE DIFFERENCE IN SUSCEPTIBILITY TO CATTLE PLAGUE 

 ENCOUNTERED AMONG CATTLE AND CARABAOS. 



By E. H. RuEDiGER. 



{From the Serum Section, Biological Laboratory, Bureau of Science, 

 Manila, P. I.) 



Perhaps the most perplexing probleia the worker with cattle plague 

 meets is the dosage of anticattle-plague serum necessary for protective 

 and curative purposes. 



Rogers/ working in India, prepared anticattle-plague serum and determined 

 itb immunizing value on seven head of plains cattle which had never suffered 

 from cattle plague. They received 10, 10, 15, 15, 20, 25 and 30 cubic centi- 

 meters of serum, respectively, per 300 kilograms of weight, and 1 cubic centi- 

 meter of virulent blood. Three animals showed mild symptoms of plague, two 

 showed moderate rise of temperature, and the remaining two did not react at 

 all. The reactions were entirely independent of the quantity of servim the 

 animals had received, showing a difference in susceptibility. 



In his second test, Rogers used 15, 20, 25 and 35 cubic centimeters of serum, 

 respectively, per 300 kilograms of weight on four animals. The first three 

 reacted well. Eleven other cattle were given 20 cubic centimeters of serum and 

 ] cubic centimeter of virulent blood. Eight reacted moderately and three did 

 not show any reaction. 



Of the twenty-two head of plains cattle reported on by Rogers, eight did not 

 react to inoculation with 1 cubic centimeter of virulent blood. From eight to 

 ten days after the first inoculation, these eight animals received 10 cubic centi- 

 meters of virulent blood each, and in five of them this inoculation was followed 

 by good reactions. 



It is to be regretted that throughout this work Rogers did not use any control 

 animals, for all or nearly all his animals might have had only a mild reaction 

 without any serum. 



Having found wide variations in susceptibility among cattle on the plains 

 where cattle plague had been endemic and epidemic for many years, Rogers resorted 

 to mountain cattle from districts that had never been visited by cattle plague, 

 hoping that these would react uniformly to inoculation. 



Doses of 10 cubic centimeters of serum per 300 kilograms of weight were 

 worthless against 1 cubic centimeter of virulent blood. Of eight animals so 

 inoculated, seven died of cattle plague. On increasing the quantity of serum 

 to 40 cubic centimeters, 50 per cent, and with doses of 90 cubic centimeters, 66 

 per cent of the cattle were saved. 



^Ztschr. f. Hyg. (1900), 35, 59. 



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