Ichthyosis in the Belgian White and Red cattle breed

Abstract

Three neonatal Belgian white and red calves with a thickened and rigid skin, characterized by the presence of scaly plates separated by deep reddened fissures were presented for necropsy. The least affected calf still had a normal hair coat, whilst the other two cases were alopecic and additionally displayed eclabium, ectropion and microtia. Based on these findings, ichthyosis fetalis bovis was diagnosed. Histological examination of skin samples obtained after euthanasia revealed an exuberant orthokeratotic hyperkeratosis of the stratum corneum. In human harlequin ichthyosis, a disorder highly resembling bovine ichthyosis fetalis, a defective lipid transport in keratinocytes caused by a single locus autosomal recessive gene defect has recently been identified as the cause of the disorder. Pedigree information of the calves combined with additional information of three other calves of the same breed allowed the identification of 3 disease carrying bulls and suggests an autosomal recessive inheritance of bovine ichthyosis fetalis. As there is currently no cure for this lethal disease, a proper breeding program is the only option to minimize the incidence of ichthyosis in this specific cattle breed.