Fragile, open skin and eviscerated intestines were the obvious signs of disease in a newborn Westphalian filly that tested positive for a newly discovered syndrome affecting Warmblood horses.

Swiss researchers recently diagnosed and reported the first-ever confirmed homozygous case of Warmblood fragile foal syndrome (WFFS), said Chloé Monthoux, DVM, of the Vetsuisse Faculty Clinic of Reproductive Medicine at the University of Zurich. The 2013 release of a genetic test for WFFS by Nena Winand, PhD, of Cornell University in Ithaca, New York, made the diagnosis possible.

A homozygous case of any condition is one in which both parents transfer a copy of a genetic mutation to the offspring. Compared to a heterozygous case, in which the offspring only receives one copy of the mutation instead of two, homozygous cases usually show stronger or more obvious signs of that particular mutation. With WFFS, though, it appears that clinical signs are only associated with two copies of the mutation, Monthoux said.

In an effort to start collecting data and to better understand the pathology of WFFS, the Swiss team recently published a report detailing the clinical signs of disease in the newborn foal. The foal’s 5-year-old dam showed no complications during pregnancy, but was unable to deliver the foal because the filly’s front ankles were flexed and blocking the passage. Veterinarians delivered the foal via Cesarean section and discovered a live filly with extensive skin lesions unrelated to the difficult birth, Monthoux said. (They also believed that the difficult birthing position was unrelated to her illness, she added.) Along with the skin lacerations on the legs, she also had an open abdomen, and some of her intestines had come through the opening. The filly’s complications were so severe that the veterinary staff and owner opted to euthanize her