The Nodular Venereal Disease 



287 



The nodules are also recognizable upon digital palpation, 

 since the elevations are very evident to the sense of touch. 

 At times digital palpation may have an advantage over 

 vision, because the mucosa may be edematous to such a de- 

 gree that, even when the nodules are abundant, they are 

 rendered invisible. 



/, Vulvi 



Fig. 80— Mild Nodular Venereal Disease. Heifer. 



2, clitoris surrounded by nodules ; 3, hymeneal scar ; 7, vagina. 



Under the prevailing conditions in American dairy herds, 

 and presumably in the dairy herds of the world, calves usu- 

 ally develop clinical signs of the disease at from four to 

 twelve weeks of age, and from that time through adult life 

 to old age present a series of interesting vacillations of in- 

 tensity, so great that various writers have designated the 

 disease as acute, subacute, chronic, cured, sound, etc. 



In the newborn heifer calf, the vulvar mucosa is usually 



