Study Links Neuroproteins to Neonatal Maladjustment Syndrome in Foals

Katarzyna Dembek, an associate professor of clinical sciences at NC State and lead researcher, explains that NMS is a complex condition affecting foals, typically manifesting as neurological signs at or shortly after birth. While foals can recover if brain damage is ruled out, the underlying mechanisms of NMS remain unclear.

Common clinical signs of NMS include an absent nursing reflex, while severe cases may result in seizures or coma. Treatment mainly involves using a feeding tube or assisting the foal in drinking from a bucket until they can be weaned, alongside supportive care for severe cases.

Dembek’s team focused on three neuroproteins: brain-derived neurotrophic factor (BDNF), glial-fibrillary-acidic protein (GFAP), and astrocytic protein S100B, which are known to aid in diagnosing various neurological diseases in humans but have not been widely studied in foals.

The study involved blood serum and plasma measurements from 14 healthy foals and 58 hospitalized foals, including 19 diagnosed with NMS. Samples were collected upon admission and again on days one and two of hospitalization.

In addition to neuroproteins, the team examined levels of three neurosteroids linked to progesterone that impact neuronal function. They found that while healthy foals exhibited a swift decrease in these neurosteroid levels, foals with neurological symptoms maintained high levels for several days. This pattern was used to corroborate NMS diagnoses in the affected foals.

The results indicated that pregnane levels in NMS foals were consistently higher than in both healthy and other sick foals. The research showed that BDNF levels decreased within the first day for NMS foals, while S100B was elevated in septic foals with NMS compared to those without. GFAP levels were lower in both NMS and sick foals compared to healthy ones.

Dembek concluded that these findings suggest that pregnanes and specific neuroproteins, especially BDNF and S100B, could serve as biomarkers not only for NMS but also for conditions like prematurity and sepsis. Additional research is required to explore practical applications of these biomarkers in clinical settings and to enhance understanding of their dynamics.

The findings are detailed in the Journal of Veterinary Internal Medicine and were funded by the Morris Animal Foundation. The study's first author is Javier Perez, a former resident at NC State now with Veterinary Associates Equine in New Zealand, with contributions from researchers across several institutions.