Histopathology of skin wound of dog. (A) At day 0 stained with H&E. a, large wound gap with complete loss of epidermal and dermal cell layer and exposure of the subcutaneous tissue; b, thrombus formation at the margin of the wound intensely infiltrated by polymorph nuclear cells associated with extravagated RBC’s. (B) At day 14, stained with Masson’s trichrome. a, control group showing faint blue stained collagen fibers; b, Panthenol-treated group showing faint blue stained collagen fibers; c and d, Hypericum niosomal gel 1.5% NaCMC-treated group showing intense blue well-organized collagen bundles. (C) At day 21, stained with H&E. a, control group showing closure of the wound gap with attenuated epidermal differentiation; b, Panthenol-treated group showing re-epithelization and keratin formation; c and d, Hypericum niosomal gel 1.5% NaCMC-treated group showing fully re-epithelialized wound with dermal reconstruction, restoration of skin appendages and appearance of hair follicles (arrow) as well as marked contraction of the wound opening.