REPORT ON DOl'RIXK. <17 



Developmental forms of the organism are to be found in fluid 

 collected from the secondary swelling arising at the seat of a sub- 

 cutaneous inoculation with blood from the general circulation of a 

 Dourine-affectod horse into a susceptible animal. 



In the great majority of instances, mares which contract 

 Dourine from an affected stallion during coitus will sooner or later 

 develop the trypanosoma in the vaginal mucus, and it may be observed 

 at intervals in the mucus during the remaining course of the disease. 



Mares subcutaneously inoculated with virulent Dourine blood, 

 in parts of the body other than the external genital organs, may 

 exhibit cutaneous plaques and later cerebro-spinal symptoms, but 

 the vaginal mucus in such cases when free from blood may remain 

 a non-infected agent. 



The vaginal mucus of a mare covered by a Dourine-infected stal- 

 lion has been found to contain the trypanosoma of Dourine some 

 months later, without the animal exhibiting any symptom of the 

 disease or of ill health. 



Flies may convey the trypanosoma of Dourine and produce in- 

 fection in healthy susceptible animals, as is the case with the Surra 

 trypanosoma, by direct inoculation, but no evidence has been brought 

 forward up to the present time to show that flies act as an inter- 

 mediary host. 



Just as cattle and camels are capable of bearing the trypanosoma 

 of Surra or its developmental forms in their blood, for periods from 

 one to three years, so certain breeds of horses can maintain the 

 ' materies morbi ' of Dourine in their systems for periods of from 

 one to four years in India. 



Section XII. NOTES ON VESICULAR EXANTHEMA OF HORSES. 



Vesicular Exanthema in horses is usually benign in character, 

 although the severe form may occur accompanied by grave compli- 

 cations such as high fever, suppuration, and emaciation, which form 

 occasionally terminates in death. Infection is usually conveyed 

 from animal to animal by coition, but mares may become infected 

 from other mares- Young sucking animals may contract the 



VI 



