Overview
The cow's uterus (uterus) is suspended from the roof of the pelvis and abdomen by the broad ligament (mesometrium). In the heifer and the non-pregnant cow it lies largely within the pelvic cavity or at the pelvic inlet; during pregnancy it sinks into the abdomen, mainly on the right, because the rumen fills the left.
Parts
- Horns (cornua uteri): long; caudally they run together, joined by the intercornual ligaments, then diverge and curve first cranially and ventrally and then caudally and dorsally, in a spiral, like a ram's horns. This external union makes the body look longer than it is.
- Body (corpus uteri): short; most of what looks like the body is the joined horns.
- Caruncles (carunculae): rounded, non-glandular raised areas of the mucosa arranged in rows. In pregnancy they join the cotyledons of the chorion to form the placentomes of the cotyledonary placenta.
- Cervix (cervix uteri): long, thick-walled and firm, with annular folds that close the canal and make it hard to pass. Its firmness makes it the main landmark of the genital tract on rectal palpation.
Clinical relevance
- Rectal palpation and ultrasound: the cervix is located first and, from it, the body and horns. Pregnancy diagnosis relies on horn asymmetry, the slip of the fetal membranes, the amniotic vesicle, the placentomes, the fetus and the fremitus of the uterine artery; transrectal ultrasound allows an earlier diagnosis.
- Artificial insemination: the catheter is guided through the cervical folds with one hand in the rectum.
- Puerperal metritis: uterine infection in the days after calving, often following retained fetal membranes; it causes a fetid discharge and can affect the general condition.
- Endometritis and pyometra: pyometra comes with a persistent corpus luteum and no signs of oestrus.
- Uterine prolapse: the uterus everts through the vulva shortly after calving, often with hypocalcaemia. It is an emergency.
- Uterine torsion: at the end of pregnancy or during calving, the uterus rotates on its long axis; it is recognised by spiral folds in the vagina.
- Freemartinism: the female twin of a male is usually sterile, with an underdeveloped genital tract, because of the exchange of cells and hormones between the two fetuses.