Bulbourethral gland

The bulbourethral glands or Cowper's glands (named for English anatomist William Cowper) are two small exocrine and accessory glands in the reproductive system of many male mammals. They are homologous to Bartholin's glands in females. The bulbourethral glands are responsible for producing a pre-ejaculate fluid called Cowper's fluid (known colloquially as pre-cum), which is secreted during sexual arousal, neutralizing the acidity of the urethra in preparation for the passage of sperm cells. The paired glands are found adjacent to the urethra just below the prostate.

Most species of placental mammals have bulbourethral glands, but they are absent in Caniformia and Cetacea. They are the only accessory reproductive glands in male monotremes. Placental mammals usually have one pair of bulbourethral glands, while male marsupials have 1–3 pairs. Of all domesticated animals, they are absent only in dogs.