The nocardioform placentitis outbreak in Kentucky’s 2011 foal crop was concerning to the equine industry. While not on as large a scale as seen in 2011, more cases of the disease are being confirmed in the 2017 foal crop in Kentucky than in the last several years (Figure 1).

Nocardioform placentitis was first identified and characterized in the mid-1980s. Sequencing of the causative agents led to the term “nocardioform” due to the phylogenic relatedness of this large family of bacteria. The most common organisms have been identified as various Amycolatopsis and Streptomyces spp and Crossiella equi. Outcomes from nocardioform placentitis can range from abortion, delivery of weak but viable foals, or delivery of normal foals; all outcomes are dependent upon the severity of the placentitis. In some cases, foals are not viable and are euthanized.

In 2011, due to subsidies paid for placental submissions and examination, the response from the local equine industry was exceptional and the University of Kentucky Veterinary Diagnostic Laboratory (UKVDL) witnessed the largest number of nocardioform placentitis cases submitted on record. The good news was that 70% of the 2011 cases resulted in viable foals.

Concerns of increased incidence of nocardioform placentitis in the 2017 foal crop surfaced in December 2016 with a local veterinarian indicating he was seeing an increase in cases. Pathologists and epidemiologists at the UKVDL also noticed an increase in cases submitted to the lab in January 2017 and alerted local practitioners and farm managers through listserv and social media