News and Information on Herd Health, Livestock and Reproduction
Dr. Misty Edmondson on Trichomoniasis in Cattle
Auburn, Alabama —
Bovine trichomoniasis, commonly referred to as ‘Trich’, is a sexually transmitted disease caused by the protozoan Tritrichomonas foetus (T. foetus). Trichomoniasis is most commonly seen on cattle farms that use natural service. Bulls do not show any signs of disease but are capable of transmitting the organism to a cow during breeding and of becoming chronically infected. Trichomoniasis in cows causes infections of the uterus and vagina which may result in early embryonic death, abortion, pyometra (pus-filled uterus detected at pregnancy examination), or infertility; all of which have a negative impact on the reproductive performance and economic profitability of a cow-calf farm.
Tritrichomonas foetus is transmitted when an infected bull breeds a susceptible cow or heifer, or when a susceptible bull breeds an infected cow or heifer. T. foetus is rarely transmitted by contaminated semen or artificial insemination (AI) equipment, especially if semen is purchased from reputable AI studs and used with sanitary AI techniques. Reputable AI studs have strict biosecurity and quality control measures in place to ensure that the semen is not contaminated with T. foetus. Therefore, AI using sanitary techniques with semen from a reputable source is an excellent way to prevent the introduction of T. foetus. However, AI may not be practical in larger herds. Some factors that put a herd at risk for acquiring and maintaining trichomoniasis include using natural service, using leased or borrowed bulls or introducing any non-virgin bulls into a herd without prior testing, and large herd size (smaller herd size decreases exposure potential because fewer bulls are needed). Trichomoniasis is usually self-limiting in cows and heifers (they will usually clear the infection in 2 to 6 months), as opposed to bulls that typically become infected for life. Unfortunately, one of the complicating factors associated with trichomoniasis is that there are currently no effective treatments that are approved by the Food and Drug Administration. Therefore, infected bulls must be culled.
Most control efforts have targeted identification and elimination of positive bulls, vaccination of at-risk cows and bulls, and management strategies to prevent introduction of the organism into the herd. These management strategies focus on herd health practices that control animal movement and biosecurity to reduce the likelihood of infection or minimize exposure. A long breeding season allows for spread of T. foetus and hides production losses due to reduced weaning weights because of delayed conception. Utilizing a limited or defined breeding season (60 to 90 days) and culling all cows and heifers that are not pregnant after the breeding season is recommended. In addition, all bulls should be tested for T. foetus before introducing them into the herd. This test can be performed by your veterinarian. Using virgin bulls and heifers as replacements also helps minimize the risk as older bulls and cows increase the chance of purchasing an animal infected with T. foetus. If older animals are purchased as replacements, then they should be purchased from herds known to be free of T. foetus. In herds at high risk, vaccination of all breeding age females against T. foetus will increase the herd’s immunity and reduce the duration of infection.
If you suspect trichomoniasis in your cattle herd or have any questions about trichomoniasis, contact your local veterinarian, or Auburn University College of Veterinary Medicine at 334-844-4490.