This
adran has no associated
Nodyn Gweithredol
4. Viral antigen or viral RNA specific to one or more of the serotypes of the disease virus has been detected and identified in samples collected from susceptible animals and the animals are positive for antibody to disease virus structural or non-structural proteins, provided that in the case of antibodies to structural proteins previous vaccination, residual maternal antibodies or non-specific reactions can be excluded as possible causes of seropositivity.S