A three years retrospective study on the nature and cause of ocular dermoids in cross-bred calves

Abstract

Nature and cause of ocular dermoids were investigated by field studies, pedigree analysis, clinical examination and light microscopy. It was determined that ocular dermoids in cross-bred calves are genetically- transmitted defects. Calves typically were affected unilaterally or bilaterally with multiple, connected ocular  growths that clinically and histologically mimicked normal haired skin. Sites most commonly involved  included ventro-lateral limbus, third eyelid, medial canthus, eyelid and conjunctiva. Centro-corneal and anterior segmental dermoids were also observed. It is postulated from this study that bilateral ocular  dermoids are genetically-transmitted defects in Hereford cattle. Characteristics of both autosomal recessive and polygenic inheritance were observed. However, mode of inheritance and role of environment in the  pathogenesis of these peculiar and important developmental defects remain undefined. Extensive breeding  trials utilizing superovulation, embryo transfer, and pre-terminal caesarean section as well as further field  studies might be mandatory to confirm sex incidence, significance of associated somatic defects, role of  environment in phenotypic expression, and mode of transmission of ocular dermoids in cross-bred calves.

Keywords: Cross-bred calves, Dermoid cysts, Incidence, Ocular dermoids, Surgical intervention.