The bulbourethral glands or Cowper's glands (named for English anatomist William Cowper) are two small exocrine glands in the reproductive system of many male mammals (of all domesticated animals, they are absent only in dogs). They are homologous to Bartholin's glands in females. The bulbouretheral glands are responsible for producing a pre-ejaculate fluid called Cowper's fluid (known colloquially as pre-ejaculate or pre-cum), which is secreted during sexual arousal, neutralizing the acidity of the urethra in preparation for the passage of sperm cells.