Detection of influenza viral RNA after infection with FPV, FPV NS GD or FPV NS VN. Quantification of influenza viral RNA was performed by RRT-PCR in blood (A) oropharyngeal swab (B) and cloacal swab (C) at the time points indicated. The results are expressed in genome equivalent copies (GEC) of plasmid per sample and shown as means ± SD. In the case that not all the samples from a group (3/3) are positive, the number of positive samples from the total number of animals is indicated above each bar. Statistical significant differences (p < 0.05) are indicated with letters. Different letters indicate statistical difference between groups and the same letter means that no statistical difference was observed. Samples from animals in the negative group (G4) were all below the limit of detection.