Trichomaniasis increasing in Nebraska cattle
During recent months, there has been an apparent increase in reported cases of trichomaniasis in Nebraska cattle, said a University of Nebraska–Lincoln (UNL) extension veterinarian.
“Trich is a true sexually-transmitted disease caused by a protozoan,” said Richard Randle. “It causes reproductive upset and failure in cattle.”
When a cow is bred by an infected bull, she gets infected at the same time she conceives. The protozoan spreads throughout her reproductive tract, creating an inhospitable environment for the calf. So it’s a race between the infection and the calf’s development.
The calf dies in about 50 to 80 days after breeding. So the cow is bred; everything looks good and then cows begin returning back to heat late in the breeding season.
The disease is not new, Randle said, but it comes and goes and moves from one location to another. Cattle movements from ranch to ranch greatly extend its spread.
Although a vaccine exists, Randle said that it doesn’t protect cattle from becoming infected. While they can still become infected, research indicates that the disease is usually less severe and of shorter duration in vaccinated cattle. The vaccine may save some calves, he said. Without other management practices, however, producers cannot control this disease, Randle said. Bulls can become life-long, symptomless carriers, he said. Like any sexuallytransmitted disease, it travels from the bull to a cow that is then bred by another bull, spreading the disease throughout the herd. Cows can and do clear the infection over time, but they serve as reservoirs for infection.
“We can test for trich, but it requires multiple tests over several weeks to accurately confirm diagnosis, so that creates some complications,” Randle said. There are no outward signs of disease, so the best protection for a herd is to avoid commingling animals from different sources. From a replacement standpoint, get virgin bulls and heifers from reputable sources.
Producers who suspect a trichomaniasis infection should contact a veterinarian. Although UNL is working to provide information and awareness about the disease, the vet should be producers’ prime contact. — WLJ