title: Hereditary nasal parakeratosis in Labrador retrievers: 11 new cases and a retrospective study on the presence of accumulations of serum ('serum lakes') in the epidermis of parakeratotic dermatoses and inflamed nasal plana of dogs.
abstract: We report 11 new cases of hereditary nasal parakeratosis in Labrador retrievers. The disease was first observed when the dogs were 6 months to 2 years of age, and affected dogs of either sex and all coat colours. Hyperkeratosis and depigmentation were confined to the nasal planum, and affected dogs were otherwise healthy. The principal histological findings in biopsy specimens were marked diffuse parakeratotic hyperkeratosis, multiple intracorneal serum lakes and superficial interstitial-to-interface lymphoplasmacytic dermatitis. Topical applications of propylene glycol in water or white petrolatum were often effective for treatment of the dermatosis. However, continued applications were required to maintain a beneficial response. A retrospective histological study of parakeratotic inflammatory diseases of canine haired skin and inflammatory diseases of the canine nasal planum was performed. The degree of parakeratotic hyperkeratosis and the number and size of intracorneal serum lakes were evaluated. The degree of parakeratotic hyperkeratosis was greater in hereditary nasal parakeratosis specimens than that seen in discoid lupus erythematosus and Malassezia dermatitis. There were more serum lakes in hereditary nasal parakeratosis specimens than in specimens from dogs with discoid lupus erythematosus, Malassezia dermatitis, primary seborrheic dermatitis or zinc-responsive dermatosis. Significant differences in sizes of serum lakes (if present) were not seen.
authors.affiliation: Departments of Biomedical Sciences, Clinical Sciences and Population Medicine and Diagnostic Sciences, College of Veterinary Medicine, Cornell University, Ithaca, NY 14853, USA.
authors.forename: Jeanine
authors.initials: J
authors.lastname: Peters
authors.forename: Danny W
authors.initials: DW
authors.lastname: Scott
authors.forename: Hollis N
authors.initials: HN
authors.lastname: Erb
authors.forename: William H
authors.initials: WH
authors.lastname: Miller
mesh_terms: D000818:Animals; D001947:Breeding; D004283:Dog Diseases / Q000188:drug therapy / Q000453:epidemiology* / Q000209:etiology / Q000235:genetics / Q000473:pathology*; D004285:Dogs; D005260:Female; D020022:Genetic Predisposition to Disease; D007150:Immunohistochemistry / Q000662:veterinary; D008297:Male; D009518:New York / Q000453:epidemiology; D009666:Nose; D010241:Parakeratosis / Q000453:epidemiology / Q000473:pathology / Q000662:veterinary*; D010577:Petrolatum / Q000008:administration & dosage; D019946:Propylene Glycol / Q000008:administration & dosage; D012189:Retrospective Studies
chemical_list: D019946:Propylene Glycol; D010577:Petrolatum