408 
W. L. WILLIAMS. 
without any other changes in the skin, observable to the naked 
eye; while in the exanthematous disease the discolored spots are 
the results of previous eruptions, and are no larger than the parent 
ulcer (J to J inch in diameter) and regular, circular in outline, the 
pigment being most completely destroyed at the center and being 
replaced by pigment first at the periphery; while in equine syphilis 
these white patches are indefinite in extent and contour. They 
may be one-quarter to one, or even four or five inches in diameter, 
or the different patches may extend and coalesce, until the whole 
perinsel region is devoid of pigment, and when the pigment is 
replaced it is deposited hap-hazard over the entire discolored skin. 
The discolored spots in the benign exanthem are very transient, 
disappearing in ten to fifteen days, while those of equine syphilis 
persist for six to eighteen months and even longer, disappearing 
first at parts farthest from the vulva, then the margins of the 
vulva lips, and lastly the clitoris. 
The open vulva and enlarged, protruding, unnaturally dry 
clitoris, especially in young and otherwise healthy mares, is quite 
pathognomonic. The welt-like, lenticular swellings in the skin of 
• various parts of the body, the rapidly progressing emaciation 
without loss of appetite, the erratic and peculiar lameness and 
paralytic symptoms already described should, when present, suffice 
with the above to enable us to form a safe diagnosis. 
In the stallion the history of the case, whether exposed or 
not, or whether infecting mares or not, is all-important, other¬ 
wise the diagnosis is generally difficult and sometimes impossible. 
The constitutional symptoms, when present, are as characteristic 
in the stallion as in the mare, but the former may be long affected 
before developing these. 
There is usually, however, some abnormality of the external 
genitals, either of the prepuce, sheath, testes, penis or scrotum. 
The prepuce, when affected in the earlier stages, presents a 
peculiar oedematous looking swelling of variable degree, but it is 
unlike ordinary oedema, the infiltration being more fixed and 
elastic than in true oedema and not pitting distinctly on pressure; 
neither is it hard and indurated, but is yielding, painless and elastic. 
The penis when affected offers specially its pendant character; 
