78 Veterinary Obstetrics 



on the penis, but this is regular in outline, whereas in dourine 

 the depigmentation spreads out in patches. 



In the mare, about eight to ten days after infection there ap- 

 pears a well marked swelling of the lips of the vulva. The 

 mucous membrane of the vulva and vagina is intensely injected 

 and swollen and from the vulva there escapes a more or less pro- 

 fuse discharge of a mucous or muco-purulent character, which 

 soils the tail and surrounding parts. The mare urinates fre- 

 quently in small quantities, which causes pain, as indicated by 

 straining, stamping with the feet and switching of the tail. 



There seems to be an increased sexual excitement, which may 

 be, to some degree, misleading, depending largely for its expres- 

 sion upon the frequent urination, rather than upon genuine sex- 

 ual desire. 



As the disease progresses, the volume of the discharge tends 

 to increase, in some cases, assumes a dirty grayish character and 

 may become fetid. The swelling of the vulva increases, the la- 

 bise become much enlarged, are tense, elastic and glistening. 

 Their margins stand somewhat apart, so that the vulva is partly 

 open, especially at its lower commisure. 



Within a few weeks, after the advent of the disease, there appears 

 quite regularly, a characteristic loss of pignte?it in the skin of the 

 vulva and the neighboring parts. This depigmentation begins 

 along the margins of the vulva, without prior vesicular or pustular 

 eruptions, as simple, white patches, and thence extends onward in 

 irregular lines, or spots, until it may involve the entire vulva, 

 perineum and anus. The white patch, or patches, have irregu- 

 lar borders and are of various shapes and sizes. They persist for 

 several months, and, in case of the recovery of the animal, they 

 tend, finally, to disappear ; fading first at the periphery, while 

 upon the margins of the vulvar lips they persist for six months 

 or a year. (See Fig. 9). 



Of even greater significance, are the changes which occur in 

 the clitoris. Comparatively early in the course of the disease, 

 this organ becomes swollen, and, the vulva being somewhat 

 open at the inferior commissure, it becomes visible, ordinarily, 

 without mechanically parting the labiae. The secretion of sebum 

 in the prepuce of the clitoris apparently ceases, and the swollen 

 organ seems dry and glistening. Depigmentation of the clitoris 

 and its prepuce occurs early and persists for one to two years 



