Fig. 4.

Representation of the typical histopathological presentation observed in the trachea of control in CRCoV infected dogs. Left: tracheal epithelium from dog from T6 (Control). There is a full covering of long slender cilia. Epithelium is orderly and contains full goblet (mucus secreting cells are indicated by the arrow). ×400, haematoxylin and eosin. Right: tracheal epithelium from dog from T4 (NP787), necropsy day 6. There is surface debris of cells and proteinaceous material. Cilia are almost completely denuded. Epithelial cells are disorderly and devoid of goblet cells. There are inflammatory cells within the epithelium and in the subjacent lamina propria. ×400, haematoxylin and eosin.