TRYPANOSOMIASIS 451 



TRYPANOSOMIASIS. 



Dourine. 1 — Definition. — Dourine is a specific infectious 

 trypanosomiasis of breeding horses and asses, spread by 

 coitus. It is characterized by two distinct clinical stages, 

 viz., a primary stage which is a local disease of the genital 

 organs, and a secondary stage of general infection, which' 

 induces nervous symptoms (polyneuritis), skin lesions, and 

 emaciation. 



Occurrence. — Dourine probably originated in the Orient, 

 from where it spread with the Arabian horse to Europe. 

 It is widely prevalent in Russia, Rumania, Spain, and 

 Algiers. The disease has invaded Germany, Austria and 

 France and Switzerland from time to time but vigorous 

 veterinary police regulations have held it in abeyance. 

 The United States has witnessed sporadic outbreaks, the 

 infection evidently spreading from imported European 

 stallions. In 1885 it was reported in Illinois, in 1892 in 

 Nebraska, in 1901 in South Dakota (Pine Ridge and Rosebud 

 Indian reservations), in 1903 in Iowa and in 1911 again in 

 Iowa. Since this date no further outbreaks have been noted. 

 By the vigorous methods of suppression employed by the 

 United States Bureau of Animal Industry, all of the above 

 cited outbreaks' were effectually controlled and the disease 

 eventually stamped out. As dourine is a chronic disease, 

 often difficult to diagnose and usually fatal, which spreads 

 readily among breeding horses, its economic importance is 

 great. 



Etiology. — The cause of dourine is the protozoon Try- 

 panosoma equiperdum discovered and described in 1896 

 by Rouget. In the United States the presence of this para- 

 site was first demonstrated in 1911 (Iowa outbreak) by 

 Dr.- John R. Mohler of the Bureau of Animal Industry 

 which conclusively established the identity of the American 

 with the dourine of Europe, Asia and Africa. 



Natural Infection. — Susceptible mares are infected by dis- 

 eased stallions during copulation, the urethral discharges 



1 From the Arabic, meaning unclean. 



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