4 DEPARTMENT OF AGRICULTURE 



Dr. Salmon, vithgreai, kinaness and promptitude, complied with my request by 

 ■ftt once senjins to I^thbrid^e Dr. E. T. Davison, of Rushville, Nebraska, to whom 

 had been entrusted the work of dealing with dourine in Nebraska, South Dakota and 

 the other western states. 



Dr. Davison, after making a careful examination of the affected animals, had no 

 hesitation in confirming my diagnosis of dourine, and so reported to Dr. Salmon, 

 under date of :May 14. 1904.* 



I may here explain that, while Dr. Davison, like myself, entertained no doubt as 

 to the identity of the disease, his opinion, like my own, was based solely on the clinical 

 evidences presented by the affected animals, f6r although dourine had, as above 

 stated, existed in the United States for upwards of twenty years, all efforts to deter- 

 mine the specific causal organism had been entirely unsuccessful. In fact it was not 

 until the following year that the question of the identity even of the disease as found 

 iu Europe with that seen in Africa and Asia was definitely settled, for although the 

 presence of the Trypanosoma Equiperdum in French cases has been successfully 

 demonstrated by Professors Nocard and Leclainche, other investigators had utterly 

 failed to corroborate their findings. 



In 1905, however, Messrs. Buffard and Schneider, two French army veterinarians 

 who had closely studied the disease in Algeria, were able to demonstrate to the satis- 

 faction of the French authorities that the disease in France was due to the same 

 causal organism as they had found in Africa. 



Almost immediately afterwards, the contention of those who maintained that 

 dourine was invariably due to the presence of the Trypanosoma Equiperdum was still 

 further strengthened by its discovery in Hungarian cases by Professor Marek who. 

 with his compatriots Messrs. Kern and Hutyra, had previously been of the opinion 

 that the parasite did not exist in Europe and that the malady seen there was, although 

 clinically closely resembling it, of an entirely different nature from that observed in 

 Algeria by Buffard and Schneider, and in India by Pease, Baldrey and Lingard.** 



It is, however, generally admitted that the detection of the trypanosoma is much 

 more difficult in Europe than in Asia and Africa, in both of which continents dourine 

 is apparently indigenous. This being the case, it is not surprising that, until the 

 discovery of Dr. Watson last February, the organism had not been found in America, 

 especially when due consideration is given to the further fact that the lack of definite 

 clinical manifestations, often observable in Europe, is even more frequently character- 

 istic of the disease as seen on this continent. 



In Asia and Northern Africa, dourine seems almost invariably to reach a fatal 

 termination, after running a definite and fairly uniform course, lasting from about 

 three months to three years. 



In Europe, however, and to an even greater degree in America, its manifesta- 

 tions are far less regular and certain, a feature which not only renders clinical 

 diagnosis much more difficult, but may also be fairly taken as an indication that, in 

 many cases, the parasites are few in number and less active and aggressive than they 

 are in the natural habitat of the disease. This last hypothesis is borne out, as will 

 be seen from Dr. Watson's report, by his repeated failure to detect the trj'panosoma, 

 even in fairly well marked cases, and after he had thoroughly familiarized himself 

 with its appearance and, as far as possible, with its life history' and habits. 



These two features, which characterize the disease in America, together tend to 

 complicate and render much more serious the task of dealing with it in a prompt and 

 effective manner. The irregularity of the clinical manifestations and their frequent 

 lack of specific character render diagnosis uncertain and precarious, while the difficulty 

 attending the detection of the causal organism deprives us to a large extent of the 

 assistance afforded in the case of so many other diseases by the skilled bacteriologist. 



* See Davison's Report. Page 

 ** See Report of Buffard and Schneider. Page 



