Tritrichomonas foetus is a single celled flagellated protozoan parasite that is known to be a pathogen of the bovine reproductive tract as well as the intestinal tract of cats. In cattle, the organism is transmitted to the female vagina and uterus from the foreskin of the bull where the parasite is known to reside. It causes infertility, and, at times, has caused spontaneous abortions in the first trimester. Cases of infection in cattle have declined due to the use of artificial insemination. In the last ten years, there have been reports of Tritrichomonas foetus in the feces of young cats that have diarrhea and live in households with multiple cats.