86 
Surra 
Pony no. 56. 630 lbs. (continuous dosage). Received eight doses of 50 c.c. of 4 °/ 0 
solution on consecutive days. 
Trypanosomes disappeared after the first dose, but reappeared 13 days 
after the last dose. 
Effect of atoxyl used intravenously. 
Pony no. 57. 500 lbs. (continuous dosage). Received four injections of 50 c.c. of 2 °/ 0 
solution, followed by nine injections of 50 c.c. of 4 °/„ solution on consecutive days. 
Trypanosomes disappeared after first dose, but reappeared four days 
after last dose. 
Pony no. 58. 560 lbs. (intermittent dosage). Received seven doses of 50 c.c. of 4 °/o 
solution on consecutive days. Interval of six days followed by four doses of 50 c.c. of 
8 °/ 0 solution on consecutive days. 
Trypanosomes disappeared after first dose, but reappeared 29 days 
after the treatment was discontinued. 
Atoxyl alone, administered in non-toxic doses, either by mouth, sub¬ 
cutaneously or intravenously, does not cure cases of surra. 
Arsacetin. 
(Sodium salt of acetyl—amino phenyl arsenic acid.) 
This preparation is said to be much less toxic than the atoxyl. 
Pony no. 59. 250 lbs., received subcutaneously 50 c.c. of 4 u / 0 solution. Died on 
5th day. 
Pony no. 60. 260 lbs., injected 100 c.c. of 4 °/ 0 solution. Died on 6th day. 
Pony no. 61. 450 lbs., injected 200 c.c. of 4 °/ 0 solution. Died on 7th day. 
Pony no. C 30. 310 lbs., injected 200 c.c. of 4 °/ 0 solution. Off feed, colic, lying 
down, unable to rise. After nine days the symptoms passed off and the animal recovered. 
This pony was in an advanced stage of surra (16 days of the disease) and trypanosomes 
were numerous in the blood at the time of treatment. The trypanosomes were absent 
from the circulation next day. The animal has been kept under daily observation for 
months and shows no reappearance of the disease. 
Arsacetin does not appear to be less toxic for the horse than atoxyl. 
Treatment with arsenious acid alone. 
Arsenious acid was administered in form of: 
Arsenious acid (bolus). 
Loeflfier and Ruehs’ solution (drench). 
