The major vestibular glands; two small glands, one in each wall of the vaginal vestibule of the cow, cat and occasionally the sheep that secrete mucus; their ducts open on either side of the urethral orifice. They secrete mucus, providing lubrication for coitus and for the passage of the fetus at birth. When cystic in the cow they are visible through the mucosa and are about 1 inch long and 0.5 inch wide. They are homologs of the bulbourethral glands in the male. Called also Tiedmann's or Duverney's gland, vulvovaginal gland.