Bovine Genital Campylobacteriosis
Description Bovine genital campylobacteriosis is a venereal disease of cattle characterized primarily by early embryonic death, infertility, a protracted calving season, and occasionally abortion. Distribution is probably worldwide.
Cows are systemically normal, but there is a variable degree of mucopurulent endometritis that causes early embryonic death, prolonged luteal phases, irregular estrous cycles, repeat breeding and, as a result, protracted calving periods, assuming the breeding season is long enough to allow for complete clearance and a successful rebreeding. Observed abortions are not common. In herds not managed intensively, disease may be noticed only when pregnancy examinations reveal low or marginally low pregnancy rates but, more importantly, great variations in gestation lengths, especially when the disease has recently been introduced to the herd. In subsequent years, infertility is usually confined to replacement heifers and a few susceptible cows. Bulls are asymptomatic and produce normal semen.
Campylobacteriosis and trichomoniasis are similar syndromes, and investigations should be directed at both diseases. Systemic antibody responses are not helpful because they are often due to nonpathogenic Campylobacter spp . A vaginal mucus agglutination test (VMAT) is useful, but due to variability in individual responses, at least 10% of the herd or at least 10 cows should be sampled. An ELISA test has been developed for use on vaginal mucus and is said to be more sensitive and able to detect a wider range of antibody responses than the VMAT.
Vaginal culture immediately after abortion or infection can be used for diagnosis, but the number of organisms may be low; in addition, because C fetus is labile and requires special techniques for isolation, success is limited.
An accurate diagnostic method is to test-breed heifers and then examine them for infection, but this is seldom practical. More often, the preputial cavity and fornix are either scraped and aspirated with an infusion pipette or infused with buffered sterile saline, and the prepuce is massaged vigorously in the area of the fornix. The aspirate or sheath washing is then examined using a fluorescent antibody test and culture. C fetus will survive for only 6-8 hr after collection, but inoculation into Clarks or similar media will allow survival for >48 hr. For maximum accuracy, bulls should be sampled twice, about 1 wk apart. Caution should be exercised when Campylobacter spp are isolated from the placenta because of the possibility of contamination by nonpathogenic fecal Campylobacter spp . Conversely, failure to successfully isolate C fetus from an infected aborted fetus or placenta often results from overgrowth of the colonies by contaminating organisms or the lethal effects of atmospheric oxygen.