Tritrichomonas foetus is a venereal disease of cattle that has a clear pattern of adverse reproductive sequela in the affected female, with a carrier state in the bull in which he shows no outward signs. Given sexual rest and symptomatic treatment, the female returns to reproductive viability. In contrast, the male remains infective and is a risk to other female contacts. Prevention of the disease relies on excluding infected males and females from the population of susceptible cattle. Control of this disease requires a plan to identify, isolate, and treat infected females, and eliminate or cull infected males. Improvements in culture technique and the application of newer methods, such as polymerase chain reaction, enhance the likelihood of detecting infected animals.