Campylobacteriosis in Ox: Fertility Problems and Venereal Spread

Campylobacteriosis in cattle, also called bovine genital campylobacteriosis or vibriosis, is a bacterial reproductive disease caused by Campylobacter fetus subspecies associated with the genital tract. It spreads mainly through breeding, especially in herds that use natural service. Bulls can carry the organism in the prepuce without appearing ill, then pass it to cows during mating.

The disease usually shows up as a fertility problem rather than a visibly sick animal. Cows are often bright, eating normally, and afebrile, but the infection can cause inflammation in the reproductive tract, early embryonic death, repeat breeding, prolonged luteal phases, and irregular estrous cycles. Abortions can happen, but they are less common than poor conception and delayed pregnancy.

For many herds, the first sign is economic rather than dramatic: more open cows, more returns to heat, and a stretched-out calving season. In newly exposed herds, pregnancy rates may drop noticeably. In later years, problems may be concentrated in replacement heifers and other susceptible females.

Campylobacteriosis is caused by genital infection with Campylobacter fetus, most importantly strains linked to venereal spread in cattle. The classic route is natural breeding with an infected bull. The organism lives in the bull's preputial cavity, especially in older bulls with deeper epithelial folds, allowing long-term carriage without obvious illness.

After breeding, susceptible cows and heifers can develop infection in the vagina, cervix, uterus, and oviducts. Conception may still occur, but the infection can interfere with early pregnancy and lead to embryonic death, delayed return to estrus, or temporary infertility. Some females eventually clear infection and conceive later, while others remain subfertile for longer periods.

Risk rises when herds use multiple natural-service bulls, borrowed or leased bulls, commingled breeding groups, or limited pre-breeding testing and vaccination. Artificial insemination lowers venereal exposure when semen handling is well controlled. Because trichomoniasis can cause a very similar reproductive pattern, your vet will often consider both diseases at the same time.

Diagnosis starts with the herd story. Your vet will look at breeding method, bull age and source, pregnancy rates, repeat breeders, and whether the calving season has become more spread out. In many herds, that pattern is the first clue. Because bulls are often clinically normal, a normal physical appearance does not rule infection out.

Testing may include vaginal mucus agglutination testing or ELISA on vaginal mucus from multiple cows, plus culture, immunofluorescence, or PCR on preputial washings or scrapings from bulls. Merck notes that herd sampling matters because individual responses vary, and bulls may need to be sampled more than once for better accuracy. Samples also need careful handling because the organism is fragile outside the body.

Your vet will usually build a differential list that includes trichomoniasis, leptospirosis, uterine disease, and other causes of infertility or abortion. That is important because the treatment and herd-control plan can change depending on which reproductive disease is present. A diagnosis is often made from the combination of reproductive history, herd pattern, and targeted laboratory testing rather than one sign alone.

Prevention focuses on breeding biosecurity. The most effective step is to reduce venereal exposure by using artificial insemination when practical or by breeding only with virgin or test-negative bulls. Be especially cautious with older, purchased, rented, or loaned bulls, because they can carry the organism without any outward signs.

Work with your vet on a pre-breeding plan. Merck lists vaccination for campylobacteriosis before breeding in heifers and annually before breeding in cows, and also before breeding in bulls where used in herd programs. Vaccination can be a helpful control tool, but it works best alongside testing, bull selection, and strict movement control rather than as a stand-alone fix.

Quarantine and evaluate incoming breeding animals, avoid sharing breeding bulls between herds, and keep clear records on conception rates, returns to heat, and calving distribution. If fertility suddenly drops, investigate early. Fast action can limit another full season of open cows and delayed calves.