Polymelia (Thoracomelia) and radial dimelia in a lamb

Different types of polymelic cases have been reported in the ruminants which most of them have been classified as heterotopic polymelia or polymelia in conjoined symmetrical twins.This article is describing a rare case of heterotopic polymelia with radial dimelia in a newborn lamb which died after 2 days due to unknown reasons. Radiographic and anatomic evaluation revealed that duplication of the ectopic limb extended proximally up to the elbow joint and two radius bones are present in it. In the polymelic cases which duplication of the limb affects zeugopodium, usually the lateral segment of this region (Ulna or Fibula) involves duplication and the medial segment (Radius or Tibia) remains single or may not form. Human radial dimelia has been reported as a very rare case, but according to the authors knowledge this is the first report of this anomaly in animals.