Updated May 2011
Campylobacter is a gram negative bacteria that can cause early embryonic death, infertility, prolonged calving season and occasional mid to late term abortion in cattle. Campylobacter fetus venerealis and C. fetus fetus are two of the common strains to cause these problems.
C. fetus can be transmitted venereally, by contaminated instruments, bedding, or with contaminated semen when artificially inseminating cows. Bulls can vary with susceptibility to become infected; some can clear the infection, while others may become permanent carriers. Generally younger bulls are more likely to clear the infection on their own, and older bulls are more likely to be the permanent carriers. Cows also vary with duration of infection some rapidly clearing the organism while some may remain carriers for longer than two years.
Cows rarely show clinical signs but may occasionally have vaginal discharge due to uterine infections. The only signs may be a large number of open cows when pregnancy checking, extended calving season duration, infertility, or some mid to late term abortions. These signs can depend on extent of infection, breeding season, and/or management practices.
The disease is difficult to treat, but easy to prevent. The vaccines are very efficacious. It is best to vaccinate all cows prior to the breeding season and all bulls as well (a double dose is recommended for bulls). Also using younger bulls will help decrease the problem if a herd has a history of the disease but this is typically not as cost effective as simply vaccinating. Generally speaking all beef herds should be using the vaccine. The oil base vaccines have a longer duration of immunity and allow for vaccination further away from the breeding season.