Campylobacter fetus subspecies veneralis is a species of Gram-negative bacteria of veterinary importance.
Bulls are carriers of the disease as they show no clinical signs but bacteria can be found in the glandular crypts of the bulls prepuce. Campylobacter fetus subsp. venerealis is therefore spread by coitus or rarely by artificial insemination. It causes catarrhal inflammation in the female genital tract, temporary infertility and prolonged oestrus cycle. Endometritis prevents implantation until the infection is cleared and causes early embryonic death and occasionally sporadic abortion.