Animal Science Department


Date of this Version



Published for the Proceedings, The Range Beef Cow Symposium XIX December 6, 7 and 8, 2005, Rapid City, South Dakota.


Trichomoniasis is a venereal disease of cattle that has caused significant economic losses in American cattle herds for many years. Its return to prominence in South Dakota in 2004-2005 is contrasted by the long-standing more endemic nature of the disease in other western states. The rate of diagnosis of trichomoniasis in the region has increased in recent years; whether this is due to an actual increase in numbers of affected herds or simply heightened awareness of the disease is not clear.

Few detailed studies have been conducted to determine the actual prevalence of trichomoniasis in U.S. herds, but a 1990 survey of California beef herds revealed that 15.8% of herds had at least one affected bull, with a total of 4.0% of all bulls testing positive. In a survey of Nevada samples in the mid-1980’s, 26.7 - 44.1% of ranches that submitted samples had a positive bull.

Economic losses in affected herds occur due to smaller and less uniform calf crops, costs of culling and subsequent replacements, and increased veterinary expense. Models have put the drop in income from the presence of trichomoniasis in a herd at 22-37%. In 2000, a group of Colorado producers figured the impact of trichomoniasis in their herd at $143.17 per cow. Some estimates of the national loss due to this disease are as high as $650 million.