Typically protruding vaginal masses are caused
by vaginal hyperplasia, but since Oreo was spayed young we shouldn't be seeing this condition; other causes like vaginal prolapse or vaginal tumours are possible so it is important to have your Veterinarian examine Oreo to determine a cause.
A mass protrusion from the
vaginal area (canine
vaginal prolapse or
vaginal hyperplasia) can be described as
vaginal tissue protruding from the vulva, commonly caused
by edema (fluid retention) from estrogen produced in estrus (when your dog is in heat).