Birth of a Live Foal after Transabdominal Ultrasound-guided Cardiac Injection of a 200-day Equine Twin Fetus

In horses, development of twins is often problematic and may represent a potential life-threatening condition for the mare and both of the embryos/fetuses. There have been many attempts at various stages of gestation to reduce twin fetuses to a singleton with variable success. Techniques have been described to perform transabdominal ultrasound-guided cardiac injection of a toxic substance into a twin fetus. The case discussed in this report is of a mare that presented at 200 days with twin fetuses. Procaine penicillin was injected directly into the heart of one fetus, using an ultrasound-guided approach. The ultimate outcome was birth of a live healthy filly, followed by the passage of a mummified fetus. This report is the first to describe the procedure in a mare at more than 168 days of gestation, leading to birth of a live foal that lived longer than 3 days.