572 DISEASES OF THE HOKSE. 



stimulating peristalsis of the bowels, which, as a result of the disease, 

 show a tendency to become torpid during the fever. Purgatives, 

 on account of their debilitating eifect, should not be given unless 

 absolutely necessary, but laxatives and easily digested feeds should 

 be given instead. Not infrequently a dirty yellowish tinge of the 

 visible mucous membranes has been observed, in which cases 20 

 grains of calomel in from 2 to 4 drams of aloes in a ball, or 2-dram 

 doses of fluid extract of podophyllin, may be given. Following the 

 subsidence of the fever, a tonic should be administered, composed of 

 the following drugs in combination : 



Arsenlous acid ^ grams-- 2 



Powdered nux vomica do 28 



Powdered cinchona bark do 85 



Powdered gentian root do 110 



These should be well mixed and one-half teaspoonful given to the 

 affected animal at each feed. 



As in the case of all other infectious diseases, the healthy should 

 be separated from the sick horses and thorough disinfection of the . 

 infected stables, stalls, litter, and stable utensils should be carried out 

 in order to prevent the recurrence of the disease. As a disinfectant 

 the compound solution of cresol, carbolic acid, or chlorid of lime 

 may be used, by mixing 6 ounces of any one of these chemicals with 

 1 gallon of water. One of the approved coal-tar sheep dips may also 

 be used to advantage in a 5 per cent solution (6 ounces of dip to 1 

 gallon of water). The disinfectant solution should be applied lib- 

 erally to all p.arts of the stable, and sufficient lime may be added to 

 the solution to make the disinfected area conspicious. 



Investigations are now in progress with a view of producing a 

 vaccine or serum that will protect horses that have been exposed 

 to the disease. 



SURRA. 



By Ch. Wabdell Stiles, Ph. D. 

 Professor of Zoology, United States Public Health Service. 



Surra is not Imown to occur in the United States, but it is more or 

 less common in the Philippine Islands and India. It is caused by 

 a microscopic, flagellate animal parasite, known as Trypanosoma 

 evansi, 20 to 34 /x long by 1 to 2 /x broad, which lives in the blood 

 and destroys the red blood corpuscles. In general the disease is very 

 similar to and belongs in the same general class with tsetse-fly dis-- 

 ease, or nagana, of Africa and mal de caderas, of South America. 



Surra is a wet-weather disease, occurring chiefly during or imme- 

 diately after heavy rainfalls, floods, or inundations. 



Surra attacks especially horses, asses, and mules, but it may occur 

 in carabao, camels, elephants, cats, and dogs, and has been trans- 



