Other abortions may occur near normal calving time and it is difficult to determine whether the cow has aborted or whether a premature birth has occurred. This NebGuide will discuss some of the known protozoal, bacterial and viral diseases that cause abortions in cattle. Protozoal Diseases Trichomoniasis. Caused by the protozoal organism Tritrichomonas foetus , trichomoniasis is a venereal disease that can cause abortions and infertility. Infected cows or heifers may have a uterine discharge for several months.
Vaccines are available but their efficacy has been questioned.
A diagnosis of trichomoniasis is made by identifying T. foetus in properly prepared preputial or vaginal fluids. The assistance of a veterinary diagnostic laboratory usually is necessary for an accurate diagnosis. Sarcocystis species are protozoa that occasionally cause abortion in cattle. Abortions can occur at any stage of gestation. There is no effective treatment for cattle infected with Sarcocystis .