Tritrichomonas foetus (bovine strain) is morphologically identical to Tritrichomonas foetus from cats (diarrhoeal pathogen), but differs slightly genetically. There is no definite evidence that cats are a source of infection for cattle under natural conditions. Genetically also closely related is Tritrichomonas suis. Differentiation of the pathogen from contaminating trichomonads from the intestinal tract or the environment can be performed by PCR.
The main site of infection in bulls is the preputial cavity. In cows, the vagina, uterus and fallopian tubes are colonised. The pathogens can persist there for up to 7 months. Clinically, cows are noticeable due to premature abortions, frequent cowshedding, prolonged calving intervals or sterility. Bulls often show no clinical symptoms.