REPORT ON DOUIliNK. 



nature of the disease, the case, although requiring time before an 

 :ilisolute diagnosis can be arrived at, will be easy. If, however, in 

 the stallion the external local changes are only slightly marked and 

 in mares the period of their appearance has been passed, the disease 

 can then only be recognized by these animals respectively infecting 

 others, and by this means also further symptoms, viz., the 

 eruption of plaques, may be brought about at an earlier date. The 

 appearance of the cutaneous plaque or patch is the chief and most 

 important symptom to be looked for in the diagnosis of Dourine, 

 but it must here be remembered that in exceptional cases the 

 number of plaques may not exceed four in a period ot 200 days 

 \?ith periods of intermissions extending from 1 to 134 days between 

 the eruption of each, and on the other hand, there may be no 

 eruption at all and yet the mare may be in a position to infect any 

 stallion that may serve her. Not unfrequently it happens that 

 certain stallions may exhibit for long periods a latent uymptom 

 which points to the presence of Dourine, vie., swelling of the 

 sheath, but an absolute diagnosis cannot be arrived at until such 

 time as further symptoms may be developed. In such cases certain 

 depressing influences, fatigue, loss of blood, etc., have been found to 

 bring about the eruption of cutaneous plaques, so that when it is 

 important to come to a diagnosis quickly, the simple measure of 

 bleeding might be had recourse to and much time and expense would 

 be saved. A difficult but particularly pertinent question may arise 

 before a diagnosis can be arrived at, viz., how to diagnose 

 Dourine in mares when the disease is known to be present amongst 

 certain animals, but all clinical symptoms are absent? Micro- 

 scopical examination of the vaginal mucus may materially aid the 

 diagnosis, for the mature protozoon or its developmental forms have 

 been found as early as the 17th day after the infective covering, 

 and have been observed to reappear at short intervals during a 

 period of over 9 months. 



(tt) The microscopical examination of body fiuidi for the 

 presence of the parasite. The trypanosoma is always present for a 

 period in the blood or sero-sanguiuous fluid of a plaque, and in thoae 

 cutaneous lesions which persist for some time, the protozoon goes on 

 increasing until large numbers are developed (fee page 34). On the 



