Dog ichthyosis a hereditary, monogenic, cornification disorder, appearing early and persisting for life. Cornification disorders form a heterogeneous group of diseases characterised by abnormal differentiation (cornification) of the epidermis. Theichthyoses, a member of this group, are distinguishable clinically by generalised scaling and histopathologically, in most cases, by a thickened stratum corneum. In veterinary medicine, ichthyosis is now commonly classified into either epidermolytic or non-epidermolytic subtypes. Most reported cases in dogs are non-epidermolytic with heterogeneous clinical, histopathological and ultrastructural profiles.
In golden retrievers, a hereditary nonepidermolytic retention ichthyosis was diagnosed and described for the first time in 2007. More recently, the clinical, epidemiological and histopathological characteristics of this disease have been precisely analysed, and an autosomal recessive transmission mode has been proposed. Dermatological signs, visible at as early as a few weeks of age, include a mild, moderate or severe generalized scaling, initially with small to large whitish scales and progressively with blackish scales.
Ichthyosis in the golden retriever has recently spread throughout the breed because of the repeated use of champions and inbred crosses with affected or carrier dogs. Since the vital prognosis was not engaged, the disease has not been counter-selected and has thus rapidly spread throughout the breed with the frequency of the mutation now reaching 50%.
Grall, A., Guaguère, E., Planchais, S., Grond, S., Bourrat, E., Hausser, I., Hitte, C., Le Gallo, M., Derbois, C., Kim, G.-J., et al. (2012). PNPLA1 mutations cause autosomal recessive congenital ichthyosis in golden retriever dogs and humans. Nat Genet 44, 140–147.
Gross, T.L., Ihrke, P.J., Walder, E.J. & Affolter, V.K. (2005): Chapter 8: Diseases with abnormal cornification. 2.nd edt. In: T.L. Gross (ed.): Skin Diseases of the Dog and Cat: Clinical and Histopathological Diagnosis. Blackwell Science Ltd, UK, pp. 161-198.
Guaguere, E., Bensignor, E., Küry, S., Degorce-Rubiales, F., Muller, A., Herbin, L., Fontaine, J., and André, C. (2009). Clinical, histopathological and genetic data of ichthyosis in the golden retriever: a prospective study. J Small Anim Pract 50, 227–235.