AbstractObjectiveExpression of the 70‐kDa heat‐shock protein (HSP70) has been demonstrated in normal canine corneal epithelium, and inducible expression has been suggested to facilitate wound resolution through organized migration, proliferation, and adhesion of the corneal epithelial cells. Diminished expression ofHSP70 may therefore contribute to prolonged healing in the pathologic cornea of other companion animal species, including the horse.Animal studiedNormal and pathologic equine cornea was evaluated to determine whether the expression ofHSP70 is correlated with appropriate corneal epithelial wound healing.ProceduresParaffin‐embedded tissue from normal equine cornea and therapeutic keratectomies of sterile keratopathies was subject to routine immunohistochemistry forHSP70.ResultsNormal equine corneas exhibited the baseline expression ofHSP70 in the nuclei of all epithelial cells as well as the cytoplasm of the basal epithelium. Expression ofHSP70 in suspected immune‐mediated keratitis was localized to the cytoplasm of basal epithelial cells and nuclei of all epithelial cells, similar to the normal equine cornea. Expression in indolent ulcers was diminished; weak, diffuse staining was noted in the cytoplasm of all epithelial cells.ConclusionsThese findings suggest the expression ofHSP70 is induced in the normal equine cornea during re‐epithelialization and may be altered in sterile keratopathies.