Читать книгу Bovine Reproduction - Группа авторов - Страница 183

Bovine herpesvirus (BHV)‐1 is a common cause of abortion, conjunctivitis, and respiratory disease of cattle. Genital infections also occur, resulting in balanoposthitis of bulls and pustular vulvovaginitis of cows. Cattle that become infected often develop latent infection that can reactivate later, complicating BHV‐1 control in the herd. The virus is shed by the mucous membranes of the respiratory tract, conjunctiva, and genital tract and transmission occurs primarily through direct contact. Venereal transmission occurs during natural mating and through AI with contaminated semen [23].

Vaccine products containing killed or modified live BHV‐1 are available for cattle. In general, the protection induced by modified live viral products is more rapid and of longer duration than killed viral products. However, modified live BHV‐1 vaccine products are capable of establishing latency that can be reactivated under stress and have been reported to cause abortion if used inappropriately in pregnant cows [24–26]. Most modified live products available for use in pregnant cows carry a label which states that the vaccine may be used in pregnant cows and calves nursing pregnant cows only if those cattle were vaccinated with the same product within the last 12 months. In order to err on the side of caution, it is my opinion that bulls should be vaccinated with the same BHV‐1 vaccine product as the mature cow herd. Vaccine products containing modified live BHV‐1 should not be administered to bulls unless the cow herd received the same vaccine product in the previous 12 months.