title: A case of asymmetrical monocephalus dipygus (tetrapus dibrachius) in a male Holstein calf in Iran.
abstract: Dipygus is a teratological fetus with a double pelvis, genitals, and extremities. Congenital duplications in cattle are rare. Caudal duplication is more common in sheep and pigs while cranial duplications seem to be predominant in cattle. Asymmetric or parasitic conjoined twins consisting of an incomplete twin (parasite) attached to the body of a fully-developed twin (autosite). This report deals with a male Holstein calf with two extra limbs, in the pelvic region which were directed ventrally between the two normal hind limbs. The extra limbs were completely developed in one side and in other side just a bony mass were observed. So classification has been made as asymmetrical attached twins. The genital system was not affected and just one extra kidney-like structure was found. To the authors' best knowledge, this is the first report of asymmetrical monocephalus dipygus (tetrapus dibrachius) in a male Holstein calf in Iran.
authors.affiliation: Department of Basic Veterinary Sciences, Faculty of Veterinary Medicine, Amol University of Special Modern Technologies, Amol, Iran;
authors.forename: Behrokh
authors.initials: B
authors.lastname: Marzban Abbasabadi
authors.affiliation: DVM Student, Faculty of Veterinary Medicine, Islamic Azad University, Babol Branch, Babol, Iran;
authors.forename: Aliakbar
authors.initials: A
authors.lastname: Ahmadzadeh
authors.affiliation: Department of Pathobiology, Faculty of Veterinary Medicine, University of Tehran, Tehran, Iran;
authors.forename: Shahab
authors.initials: S
authors.lastname: Ramezanpour
authors.affiliation: Young Researchers and Elite Club, Faculty of Veterinary Medicine, Islamic Azad University, Babol branch, Babol, Iran.
authors.forename: Amir Reza
authors.initials: AR
authors.lastname: Hajati Ziabari
keywords: Conjoined twins; Holstein calf; Monocephalus dipygus; Tetrapus dibrachius