case_images: PMC6739741_01
case_images: Feline infectious peritonitis (FIP)-associated meningoencephalomyelitis. (a)
  Spinal cord. The meninges are expanded by large numbers of plasma cells,
  lymphocytes and macrophages (x 200, hematoxylin and eosin). (b)
  Telencephalon, lateral ventricle. The choroid plexus is markedly expanded by
  inflammation, which extends into the surrounding periventricular tissue (x
  20, hematoxylin and eosin). (c) Mesencephalon. The mesencephalic aqueduct is
  obliterated by inflammation, which extends in the adjacent tissue (x 200,
  hematoxylin and eosin). (d) Rhombencephalon, fourth ventricle. Numerous
  macrophages have a strong intracytoplasmic positive immunoreactive signal (x
  40, FIP virus immunohistochemistry)
case_images: 10.1177_2055116919856103-fig1.jpg
case_images: PMC6739741_01_10.1177_2055116919856103-fig1.jpg
case_images: fig1-2055116919856103
case_images: The underlying white matter was multifocally vacuolated with numerous dilated myelin sheaths, digestion chambers and rare spheroids (Figure 1a). At the level of the lateral aperture, the choroid plexus was expanded by large numbers of plasma cells, lymphocytes and macrophages (Figure 1b). The ependyma lining the ventricular system was effaced by a similar inflammatory population, admixed with fibrin, edema and was also forming thick perivascular cuffs often disrupting the sub-ependymal parenchyma (Figure 1c). Immunohistochemistry revealed strong intracytoplasmic immunoreactivity within macrophages associated with the inflammation (Figure 1d).
case_images: Molecular analysis of the spike gene. A 156 base pair region of the feline
  coronavirus (FCoV) spike protein gene is shown and represented in single
  amino acid code, with variant residues from the central nervous system
  sample colored and amino acid positions noted. The activation site between
  the S1 and S2 domains (S1/S2) is indicated and boxed. Amino acid positions
  are based on that for FCoV RM spike (Genbank accession #ACT10854.1) as a
  prototype sequence. Sequences were analyzed using Geneious v. 10.1.2
case_images: 10.1177_2055116919856103-fig2.jpg
case_images: PMC6739741_01_10.1177_2055116919856103-fig2.jpg
case_images: fig2-2055116919856103
case_images: The sequence information obtained from this cat is shown in Figure 2.