Perosomus elumbis in a black and white German Holstein calf

摘要

Perosomus elumbis is a rare congenital anomaly of unknown aetiology characterized by the aplasia of the lumbosacral spinal cord and vertebrae, mostly associated with multiple other malformations of the hind limbs and the urogenital and intestinal tract. This report describes a stillborn female German Holstein calf showing a complete aplasia of the lumbosacrococcygeal portion of the spinal cord and vertebral column. In addition, both hind-limbs exhibited arthrogryposis and the musculature was completely replaced by adipose tissue. Furthermore, atresia ani and recti, agenesis of one kidney, one adrenal gland, and a hypoplastic and atretic female genital tract were detected. The aplasia of the lumbosacrococcygeal spinal cord and vertebral column and the other associated malformations in the presented case of perosomus elumbis may be the consequence of a combined developmental disturbance of the caudal neural tube, notochord and paraxial and intermediary mesoderm. However, it remains unclear whether the underlying cause is due to an inherited defect or due to an unknown exogenous factor disturbing embryogenesis in a critical developmental period.