Placentitis, an infection of the placenta, is the leading cause of pregnancy loss in mares and neonatal death in the first 24 hours of life. Foals that do survive to parturition still have hurdles to overcome; many are born with a life-threatening infection called sepsis. Sepsis in foals has a high mortality rate and requires highly specialized, labor-intensive care. Identifying disease and making the decision to treat these foals, however, can be challenging due to the subtlety of early clinical signs.

So researchers at the University of Illinois are testing a new diagnostic marker of neonatal disease: alpha-fetoprotein (AFP). Melissa Prell, DVM, who completed a rotating internship at the University of Illinois (U of I) Urbana-Champagne and has since started her residency at Colorado State University’s Equine Reproduction Laboratory, presented her and her colleagues’ work on this marker at the 2016 Theriogenology Conference, held July 27-30 in Asheville, North Carolina.

Alpha-fetoprotein is a protein the fetus produces early in gestation that continues to be present into the third trimester. Researchers have recently determined that AFP levels increase in the plasma of mares diagnosed with ascending placentitis, Prell explained.

“To improve the management of septic foals, we’re exploring the advantages of AFP as a marker for sepsis,” she said. “Foals infected in-utero will be born septic. So, by using markers such as AFP, we may be able to identify sick foals early on and initiate treatment more rapidly. We hypothesize that AFP is present in high concentrations in the fetus and that it will also be increased in plasma of foals suffering from neonatal disease