Figure 2. Detection of fox circovirus–specific transcripts in brain tissue of foxes with neurologic disease showing in situ hybridization of cerebrum with fox circovirus replication initiator protein gene–specific probe (original magnification ×200). A) Negative control fox VS7100012. The serum sample from this fox was negative for circovirus, and the animal did not exhibit signs of neurologic disease. B, C) Affected foxes VS7100005 and VS7100003, respectively. Both animals had neurologic disease, and their serum samples were positive for fox circovirus (see Table 1 for more information regarding these foxes). Black arrows indicate mononuclear cells in perivascular cuffs, blue arrows show inflammatory infiltrates in the neuropil, and red arrows point to staining in neuronal somata in cerebral gray matter of circovirus–positive animals with neurologic disease.