Trichomoniasis, most commonly known as Trich, is a devastating disease affecting cattle. It causes infertility and early embryonic death, leading to a high percentage of open and/or late-bred cows. The enormous cost of open cows, the veterinary and laboratory costs for investigation and diagnosis, and the costs of culling and replacing animals can lead to considerable economic strain.
What is Trich, and how is it spread?
Trich is a venereal disease in cattle; the pathogen lives in the genital tracts of cattle and is spread from infected bulls to cows and from infected cows to bulls during breeding. Bulls carry the disease and can remain infected indefinitely. Most cows clear the infection within three to five months, but immunity is short-lived and reinfection is possible.
The only way that Trich enters a herd is through an infected animal. The most obvious avenue is by introducing an infected bull or cow into the herd. However, it’s not uncommon during shared grazing, or a breach in the boundary fence, for infected neighboring cattle to breed with—and thus infect—a herd.
What are the symptoms of Trich?
Trich does not cause any apparent illness in infected animals. The only sign that Trich is in the herd is reproductive problems—a large percentage of open cows, multiple heat cycles, and increased percentage of late-bred cows. During pregnancy diagnosis, your veterinarian might also notice an increased incidence of pyometra, or pus-filled infection of the uterus.
Depending on the number of Trich-positive bulls turned out with cows, New Mexico State University estimates the loss in the first year’s calf crop can be as high as 50%.
How is Trich diagnosed?
Trich should be suspected in herds with poor conception rates and an extended calving season. A diagnosis is confirmed by testing the bulls for the presence of the organism. To do this, your veterinarian will collect preputial scrapings from your bull and send the sample to a lab for analysis. If one bull is infected, you must assume that the whole herd is infected. Diagnosis in cows is difficult and not practical in most situations.
What are treatment and control options?
There is no treatment for Trich. Once your herd has been infected, you must cull all bulls that were part of the affected breeding group, as well as any cows with pyometra. With Trich, the best option is to practice strong biosecurity and sound management to prevent introduction of Trich into your herd.
To best prevent Trich, follow these five tips:
1. Do not introduce infected animals. Buy young, virgin bulls from a reputable breeder and perform a Trich test on all bulls as part of the pre-breeding fertility exam. Do not buy open or short bred (less than 120 days) cows.
2. Maintain good perimeter fences to segregate groups and neighboring herds.
3. If shared grazing is necessary, communication is key. Work with your fellow producers and veterinarians to implement a Trich control and prevention protocol.
4. Implement a defined breeding season and maintain good records of pasture groups and pregnancy status.
5. Vaccines are available to help offer herds protection against Trich. While the vaccines do not entirely prevent embryonic death or infertility, when administered to cows the vaccines have been shown to help decrease the reproductive consequences and help them clear the infection faster.
Unfortunately, this is not an easy disease to control once it has been introduced. The economic impact alone can cause tremendous strain on any operation. Prevention is best accomplished with strict biosecurity and by working closely with your herd health veterinarian.
