The virus causes vesicles to appear on the shaft of the penis and prepuce of the stallion. When these rupture, ulcerated areas are left and infectious material may be spread. The ulcers usually heal rapidly without complications, leaving depigmented areas. | The virus causes vesicles to appear on the shaft of the penis and prepuce of the stallion. When these rupture, ulcerated areas are left and infectious material may be spread. The ulcers usually heal rapidly without complications, leaving depigmented areas. |