The South Dakota Animal Industry Board says a reproductive cattle disease has been diagnosed in three South Dakota herds.
The board says bovine trichomoniasis, or trich, has recently been diagnosed in two Oglala Lakota county cattle herds and one herd operating in Corson and Ziebach counties.
Trichomonas foetus is transmitted between cows and bulls during breeding and can result in early term abortions. Ranchers are often unaware of the problem until the disease is established in the herd.
Signs include a high number of open cows and cows showing signs of heat when they should be pregnant.
The board is requiring that any non-virgin bull be tested negative for trichomoniasis before being sold, loaned or leased for breeding. The same rule applies to non-virgin bulls entering South Dakota.