Iowa Ag Connection - National/World News - UK Veterinary Scientists Respond to Nocardioform Placentitis

National & World Ag News Headlines

UK Veterinary Scientists Respond to Nocardioform Placentitis
USAgNet - 02/17/2020

The 2019-2020 foaling season has seen an increase in reports of Nocardioform placentitis, both in cases submitted to the University of Kentucky's Veterinary Diagnostic Laboratory and in reports from equine practitioners in the field. Nocardioform placentitis is an equine placental disease affecting pregnant mares and their foals during pregnancy.

UK's VDL provides real-time surveillance of this and other livestock diseases and has been sending reports updating practitioners and farms about what is being seen since positive tissue samples started appearing in late October. Additionally, the Gluck Equine Research Center announced at its foundation board meeting Feb. 6 that it was activating Koller Emergency Response Funds to immediately augment existing research efforts and launch new projects to study the disease while it is occurring, with an aim of understanding the disease better. Currently, early identification of the disease is a challenge, making it difficult to identify at-risk mares and treat them proactively.

"Obviously, those of us who are private equine practitioners have been working closely on a daily basis with area horseman in Central Kentucky and have been extremely engaged in sharing our experiences of Nocardioform placentitis cases from these most recent occurrences, as well as our experiences observed in previous years," said Stuart Brown, Gluck Equine Research Foundation Board chair and equine veterinarian from Lexington-based Hagyard Equine Medical Institute. "These conversations with the research team at the Gluck Center, along with specialists at the UK VDL, provide all of us a unique opportunity to collaborate on our observations to understand the presentation of these cases."

The disease, a complex and relatively rare condition caused by bacteria, primarily Crossiella equi and Amycolatopsis spp., affects the placenta of the pregnant mare and can cause foal losses from late-term abortions, stillbirths, prematurity or early neonatal deaths due to placental insufficiency.

While it is typical to see a handful of cases each year, an increase in positive cases reported usually only occurs intermittently. The last increased cluster of cases occurred during the 2017 season, and before that, during the 2011 season. While there have been similar numbers of cases reported by the UK VDL compared to the 2011 season, it is important to note that positive cases refer to all samples received, including affected placental tissues, not necessarily the loss of a foal. In fact, in many cases where the placenta might have been affected, the foal was born healthy and unaffected.

Because the Central Kentucky region lies at the heart of the world's Thoroughbred breeding industry, and is home to the world-renowned equine medical infrastructure that cares for that population, it stands to reason that the highly tuned equine health surveillance mechanisms in place would catch the disease when it occurs. Cases of Nocardioform placentitis have also been reported sporadically in Florida, South Africa, Italy and, most recently, New Zealand.

"Given the number of foals born in this area each year, the expertise of the local veterinarians and farm managers and the surveillance efforts of the UKVDL, we are well positioned to identify these types of occurrences as they emerge," said David Horohov, chair of the UK Department of Veterinary Science and director of the Gluck Equine Research Center.

"Many of our farms have experienced little or limited cases while others have noted incidence numbers that would be greater than anticipated," Brown said. "On many farms with the vigilant surveillance associated with farms in Central Kentucky, there are mares that have delivered foals of acceptable size and development from cases that have been identified by farm managers and veterinarians working together to treat suspected cases before foaling. It is these experiences that will help us solve this puzzle and help us understand the incidence of occurrence associated with Nocardioform placentitis."

Given the pressing need to develop better diagnostic tests and preventative strategies, UK is proceeding with new research projects to gain additional information about the mare's response to Nocardioform placentitis. This coordinated effort involves faculty with expertise in reproduction, microbiology, immunology and pathology, as well as collaborations with clinical partners throughout the region.

"Drs. Barry Ball, Erdol Erol, Rebecca Ruby, Allen Page, Emma Adam and Jacqueline Smith are leading this research effort, which aims to identify at-risk mares, collect samples from infected mares for further analysis and continue to screen the identified bacteria for antibiotic sensitivity and resistance," Horohov said.

Nocardioform placentitis abortions typically occur between November and June, with a peak incidence in January and February. The majority of affected pregnancies occur in the last trimester of gestation, and the identification of nocardioform lesions on the placenta of term pregnancies is a common presentation.

Other National Headlines