A hereditary disorder of cornification and multiple congenital defects in five Rottweiler dogs

The clinical, biochemical, histological, or ultrastructural abnormalities of five related female Rottweiler dogs with a hereditary disorder of cornification are reported. Three of the five dogs also had multiple noncutaneous congenital defects. Cutaneous abnormalities included generalized, hyperkeratotic, variably pigmented plaques, which in one dog were distributed along Blaschko's lines. Moderate to severe parakeratosis involving the follicular infundibula and ostia and focal orthokeratosis with variable vacuolation of spinous cells was observed on histopathologic examination of all skin specimens. Supplementation with oral zinc in two dogs and vitamin A alcohol and calcitriol in one dog did not result in clinical or histological improvement of the hyperkeratotic lesions. This disorder of cornification in dogs is similar to human disorders of cornification that follow the lines of Blaschko. Blaschko's lines follow a V‐shape over the spine, an S‐shape on the abdomen, and an axial distribution on the limbs. No related male dogs were affected, suggesting an X‐linked dominant mode of inheritance. Many features of this hereditary DOC correspond to the human condition CHILD syndrome.