73 
THE TREATMENT OF SURRA IN HORSES BY 
MEANS OF ARSENIC AND ITS DERIVATIVES. 
Tldrty-two Gases of Successful Treatment. 
By J. D. E. HOLMES, M.A., D.Sc., 
Imperial Bacteriologist to the Government of India. 
The value of arsenic in the treatment of trypanosomiasis is no new 
discovery. 
Evans (1880), who described the first pathogenic trypanosome, 
recommended the administration of arsenic. Lingard (1899), for 
many years, investigated surra in India and treated twenty-one horses 
suffering from that disease with arsenious acid. One horse survived. 
His system of treatment was, the administration of arsenic in the form 
of Fowler’s solution, commencing with 5 grains, twice daily and gradually 
increasing to 10 grains. Treatment extended over several months ; the 
total amount of arsenic given, in some instances, amounted to over 2,000 
grains. During the period of treatment intermissions of 30 to 50 days 
were recorded, but all the animals, with one exception, finally succumbed 
to the disease. Bruce (1897 and 1903), treating nagana in Zululand, 
gave 6 to 12 grains of arsenic in form of arsenite of soda to horses and 
asses suffering from that disease. Trypanosomes remained absent 
during the period of treatment, but reappeared immediately treat¬ 
ment ceased. Trelut (1907) claims to have cured cases of dourine 
by the daily administration cf 3 to 6 grammes of arsenious acid. 
Archangeliky and Novikoff (1907) also record cases of dourine cured by 
them with arsenite of sodium and cacodylic acid. Marchal (1903) 
stated that he cured five stallions suffering from dourine by subcutaneous 
injections of 1 gramme of cacodylate of soda. Loefflerand Ruehs (1908) 
record a number of successful experiments on animals affected with 
nagana, which they treated with a solution of arsenious acid. They 
