PIROPLASMOSES 485 



symptoms of general anemia are very suggestive of Texas 

 fever. In anthrax anemia does not develop. Blackleg 

 attacks only young cattle which show characteristic, crepitant 

 swellings and no splenic enlargement. The course of hemor- 

 rhagic septicemia is usually very rigorous and rapid (die in a 

 few hours), no ticks are present, the spleen is not enlarged 

 and microscopically the bipoled bacteria are visible between 

 the blood corpuscles. 



Course. — The coiu-se of the disease is varied. Acute cases 

 (height of the Texas fever season) die in three to five days. 

 Subacute cases may linger for three weeks and terminate 

 fatally. Chronic eases often recover after weeks of illness. 

 In calves the disease is often benign, ending in recovery. 

 As noted, outbreaks during very hot weather are more 

 malignant than when cooler. Chronic cases are subject to 

 relapses. The mortality is from 5 to 90 per cent. 



Treatment. — The patient should be removed at once to a 

 non-tick- infested, shady place, and if feasible, the ticks 

 removed from them (hand-picking, antiparasitic agents). 

 Internal medication avails little. Much recommended is 

 quinin (3ij to v per os). Intravenous injections of formalin 

 (100 to 500 grams of a 1 per cent, solution), followed by lysol 

 internally (I^ — lysol, 3ij; spiritus frumenti, giij; aqua, Oj; 

 M. D. S.; hourly one tablespoonful until urine becomes 

 clear) have given some results. Trypanroth given sub- 

 cutaneously or intravenously (up to 200 c.c. of a IJ per cent, 

 solution; make up fresh in distilled water) will reduce the 

 number of parasites but usually only temporarily. 



Prevention. — ^The prevention of Texas fever depends upon 

 .the eradication of the carrier-tick. Once a field is rid of these 

 insects, non-tick-bearing cattle may be turned into it with 

 impunity. The task of ridding the United States of cattle 

 ticks is now well under way. In the southern states an area, 

 formerly tick-infested, larger than two ordinary states, has 

 already been freed. Various methods of eradication are in 

 vogue. Which one to employ will depend upon local con- 

 ditions. The following briefly describes the most practical 

 methods : 



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