Spontaneous canine transmissible venereal tumor
(TVT) is a neoplasia of round cells that can be
transmitted by transplant of viable tumor cells from one
animal to another during copulation or through licking,
biting, or scratching, especially in the presence of
abrasions or loss of surface integrity. Although
extragenital localization is also possible, it occurs most
frequently in the mucous membrane of the external
genitalia of stray, sexually active medium-sized dogs, of
both sexes, and presents global distribution, though is
most common in tropical and subtropical regions