Thoracomelia in sheep: a case report

Abstract

In this case report, the occurrence of thoracomelia in a female sheep is reported. Thoracomelia is a congenital malformation that can affect several animal species and is characterized by the presence of a supernumerary limb in the thoracic region. Scientific studies regarding the etiology of changes of this nature are limited in veterinary medicine, especially concerning sheep. So far, there is no consensus regarding if the origin of this congenital malformation is genetic or environmental. Here, we provide the historical and photographic record of thoracomelia in a female sheep, and relate the malformation to an environmental cause: physical aggression suffered during embryonic development. The sheep underwent a surgical procedure for removal of the accessory limb and subsequently remained in the breeding line, giving birth to healthy descendants without thoracomelia.

Polymelia (thoracomelia), an extremely rare appearance of congenital anomalic limb in a Nepalese child and its embryological basis

“…There are several cases of thoracomelia reported in the animal species. A rare case of thoracomelia has been reported in a female sheep due to an environmental cause [ 1 ]. In a male Korean native calf, polymelia (notomelia) was observed macroscopically and radiographically.…”

“…Scientific studies regarding the etiology of changes of this nature are limited in both human and veterinary medicine. So far, there is no consensus regarding if the origin of this congenital malformation is genetic or environmental [ 1 , 2 ]. Limb malformations occur in approximately 6 per 10,000 live births and usually affect the upper limbs more than the lower limbs 3:1 [ 3 ].…”