disease is also referred to more colloquially as "vibriosis", based on the former classification of the bacteria under the Vibrio genus. Bovine venereal campylobacteriosis is primarily a problem in beef cattle breeding stock. C. fetus subspecies venerealis is an obligate colonizer of the bull penile and preputial mucosa. Infection of bulls with Cfv is a chronic, asymptomatic infection that leads to the development carrier bulls in the breeding herd. Infection of the prepuce can persist for years in bulls and is often undetected due to the lack of any visible lesions on the penis or prepuce. Younger bulls are more likely to clear the Cfv infection than older bulls, therefore transmission risk increases with bull age. Transmission of Cfv to cows occurs through mating with an infected bull. Alongside Tritrichomonas foetus, bovine venereal campylobacteriosis considered an important sexually transmitted disease (STD) of cattle. However, transmission can occur by artificial insemination with semen from an infected bull. Transmissibility from carriers to naïve cows is high, such that outbreaks of Cfv in the herd can often be traced to the introduction of a new bull. Infection sites in the cow include the vagina, cervix, endometrium, and oviducts. If the cow becomes pregnant, the placenta can also be a site of infection. Rather than the bacterial colonization itself, the ensuing inflammatory response in the uterus and oviducts is often the cause of early embryonic mortality. Loss of embryos is generally within the first 15 to 21 days of conception, indicating infection occurred near mating. Late term abortions have been reported for Cfv infections in cows, but are much less likely than early embryonic loss. Cows with BVC display irregular estrus cycles, signs of heat when presumed to be pregnant, and increased returns to service, but often lack any outward signs of infection. On a herd level, Cfv leads to widespread infertility, wide variability in calf age, longer calving seasons, and decreased calf crops. Infected cows may return to estrus up to five times before pregnancy can be maintained. Infections and pregnancy loss in subsequent calving seasons is substantially less severe than the first season of infection, as cows can mount a sufficient immune response. However, the bacteria can persist in the vaginal mucosa for years in some cows, leading to infection of bulls upon mating. It is also reported that Cfv can become endemic in cow herds, leading to a low incidence of