A NONSPECIFIC DEFENSE INDUCER IN PREVENTING CLINICAL SIGNS OF INFECTIOUS BOVINE-RHINOTRACHEITIS IN CALVES

One calf was infected with bovine herpesvirus-l (BHV-1) and mixed with five other calves, of which one had been vaccinated with a BHV-1 modi fied live vaccine one month earlier. The other four calves were vaccin ated at the time the experimentally infected calf developed the first signs of the disease (fever, depression, nasal discharge), i.e. on pos t infection day (PID) 2. In addition to the vaccine, two of the four P ID 2 vaccinated calves also received a non-specific defence (NSD) indu cer (Baypamun, Payer AG) at the same time as the vaccine. The calf tha t was vaccinated 1 month before the start of the experiment, as expect ed, did not show any signs of the disease. Of the remaining four, the two vaccine-only calves experienced a classical form of infectious bov ine rhinotracheitis. However, the two calves that had also received th e NSD inducer remained generally healthy during the entire observation period of 30 days. It was speculated that the use of a NSD inducer on ce an outbreak of a respiratory disease has started on a farm could be of significant help in an emergency in reducing the clinical manifest ations in those animals that may subsequently be infected. Copyright ( C) 1996 Elsevier Science Ltd