Organisms of both venereal diseases are usually spread during mating. However, bulls mounting each other at stud or at artificial insemination centres, and the use of contaminated grooming equipment or veterinary instruments, have all been incriminated in the spread of the infection. Campylobacteriosis and trichomoniasis cause inflammation of the vagina, cervix, uterus and fallopian tubes in the cow. This inflammation usually prevents successful implantation of the embryo in the uterus and leads to early abortion. The result is seen as cows returning to heat and poor pregnancy test results.
Young cows are usually worst-affected, because they have no previous exposure and immunity.
However, animals of any age can be infected if not previously exposed to the diseases. Introduced bulls or carrier cows are the most usual sources of infection, but infected bulls that have jumped fences to gain access to the cows are common culprits. Bulls undergoing sexual service capacity tests risk contracting and spreading campylobacteriosis and trichomoniasis if they have not been vaccinated. Prevention and treatment Commercial vaccines for campylobacteriosis will not only prevent the disease, but will also cure infected bulls. Available in 'bull packs', the vaccine is administered at a rate of 5 mL for each of two doses, the second dose being given four to six weeks after the first.