Many of these malformations are reported sporadically, but a few are common, and several have important clinical implications. One example is schistosomus reflexus, which is always a challenge for veteran clinicians and often baffling to inexperienced obstetricians. The recent finding that early palpation of the amniotic vesicle can cause intestinal atresia in calves is extremely significant for dairy practitioners. Finally, there is the ethical question in breeding animals--repairing defects that are thought to be genetic, such as atresia ani, scrotal hernia, and umbilical hernia.