BUKEAU OF ANIMAL. INDUSTRY. 233 



THE RECURRENCE OF DOURINE IN THE UNITED STATES. 



On May 27, 1911, the bureau received a letter from Dr. J. I Gibson, 

 State veterinarian of Iowa, stating that there was in Taylor County 

 an outbreak of a disease of horses, suspected of being dourine, and 

 requesting that an expert be sent to make an investigation. The 

 disease had been reported by Dr. A. H. Quin, a practitioner of Creston, 

 Iowa, and his diagnosis was subsequently confirmed on the part of the 

 bureau by Drs. A. D. Melvin, John R. Mohler, and E. T. Davison, who 

 were of the unanimous opinion that the symptoms and lesions mani- 

 fested were the most typical of any of the cases they had observed. 

 Three of the affected mares were at once purchased and sent to Wash- 

 ington for experimental purposes. After a careful and prolonged exam- 

 ination of almost 200 microscopic slides, six living, wriggling trypano- 

 somes {Trypanosoma equiperdum) were found on June 28, 1911, in the 

 blood-tinged serum obtained from a recently developed plaque on the 

 abdomen of one of the mares, thus confirming the diagnosis and also 

 establishing the identity of the disease with that of Asia, Africa, and 

 continental Europe. These trypanosomes have always been very 

 scanty and are only found after prolonged and tedious examination. 

 This is the first discovery of the Ti jpanosoma equiperdum in the 

 natural cases of dourine in the United States, although in 1903 con- 

 siderable work was done with this trypanosome imported from 

 France and subsequently inoculated into horses at the Bethesda 

 Experiment Station. Previous to 1911 there had been no authentic 

 cases of dourine reported among the horses of the United States since 

 1906, although there had been a number of alleged or suspected cases 

 brought to the bureau's attention from time to time which demanded 

 a full investigation, but always with negative results. 



In the outbreak of dourine recently discovered in Taylor County, 

 Iowa, 5 stallions have been found afi'ected and 5 exposed to this dis- 

 ease. One of the former stallions has since died of the infection. 

 In addition, 9 mares have shown symptoms of dourine, 1 of which 

 subsequently died of the disease, 5 are suspicious cases, and 94 have 

 been exposed but at present show no evidence of infection. These 

 diseased animals, together with all exposed stallions and mares,_ were 

 immediately quarantined by the State. Those showing lesions of the 

 disease were purchased by the Government and destroyed, while the 

 exposed animals are still in quarantine under observation. Several 

 Federal and State inspectors are making farm-to-farm inspections 

 with the view of discovering any latent or hidden cases, and it is now 

 believed that the infe; Uon is entirely under control. The source from 

 which this center of infection was derived is only a matter of conjec- 

 ture, but there is apparently no connection between this and any of 

 the previous outbreaks. No authentic information as to the origin 

 of the outbreak has been discovered up to the present time, but all 

 cases lead back to a Percheron stallion imported from France in 

 1909, and brought directly to Lenox, Iowa The possibility of si.<'h 

 animals bringing the infection into this country must be apparent 

 from the following explanation: 



Schneider and Buft'ard maintain that in France dourine appears 

 nearly every year in the Department of Basses-Pyrenees on the 

 Spanish frontier. It is stated th^t mares get infected by the asses 

 or horses by which they are covered. It is the custom to have a mare 



