84 Veterinary Obstetrics 



Later a depigmentation of the penis and prepuce may occur, 

 not in small circular spots, as in genital horse pox, but in large, 

 irregular patches, which gradually spread from the periphery. 

 In the mare, the most important local symptoms for purposes of 

 diagnosis consist of the doughy, edematous swelling of the vulvar 

 lips, the enlargement of the clitoris, the gaping of the vulva at 

 its inferior commissure and the depigmentation of the clitoris, 

 and its prepuce, and of the skin of the vulva, perineum and anus. 



Once it is decided that an equine venereal disease exists in a 

 stud, the presence or absence of specific pustules or vesicles may 

 serve largely to differentiate between the two maladies. 



Eruptions upon the external genitals may, of course, occur in 

 Dourine, but those writers who have mentioned them uniformly 

 fail to de-scribe them in a manner to enable one to differentiate 

 those of Dourine from those of Genital Horse Pox, and, as a 

 rule, it might well be suspected that such descriptions are based 

 upon diagnostic error. In some cases, doubtless, erosions or 

 ulcers have appeared as the result of irritation from ichorous dis- 

 charges or from the accumulations of filth about the genitals, 

 accompanied by low vitality in the cutaneous tissues ; but such 

 eruptions are devoid of diagnostic value, their relation to the 

 disease, so far as we know, being quite .secondary. 



Specific eruptions of vesicles or pustules upon the genitals do not 

 occur. When abu)idant and specific eruptions occur on the genitals 

 of the horse, they indicate Genital Horse Pox, not Dourine. 



Dourine and Genital Horse Pox may readily coexist and thus 

 add confusion in diagnosis. 



In the outbreak of Dourine in Illinois in i8<S6-7, we were in 

 great doubt for a time as to our diagnosis in the case of a young 

 stallion showing abundant pustules and vesicles on the penis, 

 prepuce and sheath. The urethral meatus was inflamed, dark 

 livid in color ; from it there was a thin grayish discharge ; the 

 prepuce and sheath were swollen. Though the animal was 

 within the zone of infection, no exposure could be traced. He 

 transmitted Dourine to no mares, and recovered completely and 

 permanently in a few days. Had it been possible to connect him 

 in any way with the outbreak, it would have been difficult to 

 attribute the eruptions to anything but Dourine, and, had he been 

 actually affected with that malady, we have no reason to believe 

 that it would have prevented his becoming simultaneously in- 



