40 REPORT ON DOUBINE. 



first appearance of cedematous collections theprotozoon can generally 

 be found, but latev numerous stained specimens may have to be 

 made before the developmental forms may be discovered ; but if 

 sufficient time and care be expended, a positive result will be 

 obtained. In this country the inoculation of susceptible animals 

 with blood or cedematous fluid of suspected cases will give results, 

 but pariah dogs react in too uncertain a fashion to be utilized, and 

 country tats may be included in the same category. Donkeys may 

 react to inoculation with infective blood and later exhibit plaques, 

 but in most instances stallions or jacks present a secondary swelling 

 at the seat of inoculation after a period of 12 to ] 5 days and in the 

 fluid drawn from this swelling the mature trypanosoma or the 

 developmental forms may be observed and a diagnosis made, 

 although no subsequent exhibition of symptoms may follow with 

 the exception of the eversion of the m. m. of the ineatus urinariue. 

 An immediate diagnosis between Surra and Dourine may not be 

 an easy one, especially in some advanced cases, unless microscopical 

 examination of the blood from the general circulation be made 

 daily until the presence of the trypanosoma has been demonstrated 

 in the case of the former disease. The extensive oedema which 

 collects on the under-surface of the abdomen in some Surra animals 

 may be simulated in cases of Dourine and occasionally almost 

 surpassed. In Surra animals the paroxysms or pyrexial periods are 

 usually accentuated by the presence of well-marked conjunctival 

 petechise, high fever and the presence in vast numbers of the 

 hseinatozoon, whereas in Douriue the temperature rarely exceeds 

 normal limits or at all events for long periods at a time, and there 

 is a complete absence of conjunctival petechiaB. The protozoon may 

 only be present in small numbers or undiscoverable on microscopical 

 examination of blood from the general circulation. Surra is an acute 

 disease absolutely fatal to equines within a few months (2 to 3) 

 of its onset. Dourine is essentially chronic in character ; death 

 rarely occurs before six months have elapsed. Vesicular Exanthema 

 has until late years been considered to be a benign form of Douriue. 

 This was accounted for by the fact that the two diseases are 

 liable to be contracted from the same animal during a single act 

 of covering. In the former disease the period of incubation may 



