Bovine Venereal Campylobacteriosis – formerly Bovine Vibriosis – is a highly infectious venereal disease of cattle causing infertility, abortion and early embryonic death. Along with leptospirosis and pestivirus, it is one of the primary causes of abortion in cattle herds across the Crookwell district. All three contribute to significant economic loss through reproductive wastage.
The causative organism – the bacterium Campylobacter fetus – is spread by carrier bulls during mating. Campylobacteriosis is strictly a venereal disease – there are no other routes of infection or spread other than mating.
Infected bulls show no signs of the disease and it is most commonly introduced into a susceptible herd by an apparently healthy carrier bull. Bulls develop the disease after serving infected cows and heifers or, if an infected bull mates with a heifer or cow, the female develops an infection in the uterus.
Effects of the disease
While carrier bulls show no symptoms, infection in females can cause early abortion, prevent implantation/conception or cause delayed conception. In these cases, the cow or heifer returns to oestrus, but often with prolonged and irregular cycles, and the calving season is longer than usual.
Following the introduction of the disease, conception rates can drop dramatically to around 40%. These figures may improve as the herd develops some immunity, but this is temporary, lasting only around a year before reinfection occurs.
Prevention
CVH stocks Vibriovax (the campylobacter vaccine). Vaccination should be undertaken as follows:
- All bulls should be vaccinated annually. This is the most effective way to control the disease.
- To start a vaccination program, bulls should first be given two vaccinations 4 weeks apart, then annual boosters.
- Before introducing a new bull into your herd (unless it comes with a certified vaccination history) give 2 vaccinations 4 weeks apart. Continue with annual boosters.
- In the face of an outbreak, vaccinate all females in the herd.
- Vaccination should be completed 4 weeks before joining.
Diagnosis
If the disease is suspected, diagnosis involves laboratory demonstration of specific antibodies in the vaginal mucous of affected cows. The organism can also be isolated from preputial fluids (less effective) or from aborted foetuses.