Results of tissues in group GP and -P. A: the C. psittaci qPCR results of tissue samples are shown. On the Y-axis the cycle treshold (Ct) value is depicted. The Y-axis has been rotated and Ct values > 40 or no qPCR signal are shown as Ct 41. The bar indicates the median. B: macroscopic enlargement of the spleen in a C. psittaci infected animal. C and D: histological examination of the spleen (same magnification, bar = 200 μm). Note the pronounced hyperplasia of the red (white arrows) and white pulp (black arrows) in the C. psittaci infected animal (D) compared to the animal infected with C. gallinacea (C).