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Journal of veterinary internal medicine2026; 40(5); aalag228; doi: 10.1093/jvimsj/aalag228

Biomarkers of brain injury in foals with neonatal maladjustment syndrome.

Abstract: Plasma concentrations of brain-derived neurotrophic factor (BDNF), glial-fibrillary-acidic protein (GFAP), and astrocytic protein S100B, might be linked to the pathophysiology of Neonatal Maladjustment Syndrome (NMS). Objective: To measure serum concentration of BDNF and S100B, plasma concentration of GFAP, and neurosteroids (progesterone and 17α-hydroxyprogesterone) in foals with NMS, foals presented for other diseases, including premature, and healthy foals, and determine their association with outcome. Methods: Fourteen healthy foals, 19 NMS foals, 39 foals hospitalized for other diseases < 7 days of age. Methods: In this prospective, longitudinal study, concentrations of biomarkers were determined in all foals on admission, at day 1 and 2 of hospitalization. Plasma or serum concentration of biomarkers was measured with ELISA and single-molecule-array technology. Results: Forty-eight foals survived, 10 did not survive. Serum BDNF concentration was lower after 24 h of hospitalization in NMS foals (baseline: 3.0, 1.9-4.1 g/mL; day 1: 2.0, 1.2-2.8 pg/mL) (P = .02). Serum S100B was higher in septic foals with NMS (marginal means, 95% CI, 435.3, 290-580 ng/mL) compared to septic foals without NMS (238.9, 164.6-313.2 ng/mL) on admission (P = .01). Pregnane concentrations were higher in NMS foals compared to healthy and sick foals over the first 48 h of hospitalization (P < .05). Conclusions: Higher BDNF, S100B, and pregnane concentrations were consistent with NMS, and might allow for neurological assessment.
© The Author(s) 2026. Published by Oxford University Press on behalf of the American College of Veterinary Internal Medicine.
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Publication Date: 2026-09-22 PubMed ID: 42770276PubMed Central: PMC13594675DOI: 10.1093/jvimsj/aalag228Google Scholar: Lookup
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  • Journal Article

Summary

This research summary has been generated with artificial intelligence and may contain errors and omissions. Refer to the original study to confirm details provided. Submit correction.

Overview

  • This study investigated specific biomarkers in the blood of newborn foals with Neonatal Maladjustment Syndrome (NMS), aiming to identify biological indicators that correlate with the disease and its outcomes.
  • The researchers measured brain-derived proteins and neurosteroids to determine how these levels differ in foals with NMS compared to healthy and other sick foals.

Background and Purpose

  • Neonatal Maladjustment Syndrome (NMS): A neurological condition affecting newborn foals, characterized by difficulty adapting to life outside the uterus, with symptoms such as abnormal behavior, weak suckle reflex, and altered neurological signs.
  • Biomarkers studied: Brain-derived neurotrophic factor (BDNF), glial-fibrillary acidic protein (GFAP), astrocytic protein S100B, and neurosteroids (progesterone and 17α-hydroxyprogesterone).
  • Objective: To measure blood levels of these biomarkers in foals with NMS, other diseases, and healthy foals, and assess whether these can help understand the disease process or predict outcomes.

Methods

  • Study design: Prospective and longitudinal, following foals over time during their first days of hospitalization.
  • Subjects:
    • 14 healthy foals
    • 19 foals diagnosed with NMS
    • 39 foals hospitalized with other diseases, including premature foals
  • Sample collection: Blood samples taken at admission, after 1 day, and after 2 days of hospitalization.
  • Biomarker measurement: Enzyme-linked immunosorbent assay (ELISA) and single-molecule-array technology were used to precisely quantify biomarker concentrations in plasma or serum.

Results

  • Survival: Out of 58 foals studied, 48 survived and 10 did not.
  • BDNF levels:
    • In NMS foals, serum BDNF concentrations decreased significantly after 24 hours of hospitalization compared to baseline (from median 3.0 to 2.0 pg/mL, P = .02).
  • S100B protein levels:
    • Septic foals with NMS had significantly higher serum S100B concentrations on admission (average ~435 ng/mL) compared to septic foals without NMS (~239 ng/mL, P = .01).
    • S100B is a protein released by astrocytes (brain support cells) and elevated levels suggest brain injury or dysfunction.
  • Pregnane neurosteroids:
    • Pregnane steroid concentrations (including progesterone and 17α-hydroxyprogesterone) were higher in NMS foals than in both healthy and other sick foals during the first 48 hours (P < .05).
    • These neurosteroids are involved in brain development and neuronal protection and might be related to NMS pathophysiology.

Conclusions

  • Elevated levels of S100B and pregnane steroids, along with reduced BDNF after 24 hours, are associated with the presence of NMS in foals.
  • These biomarkers may reflect brain injury or maladjustment processes occurring in NMS and could help in neurological assessment and monitoring of affected foals.
  • Further research is needed to establish these biomarkers as diagnostic or prognostic tools in clinical practice.

Significance

  • This study enhances understanding of the biological changes occurring in foals with NMS and identifies potential blood-based biomarkers that could support early diagnosis and treatment decisions.
  • Using such biomarkers could improve veterinary care by allowing timely intervention aimed at reducing neurological damage and improving survival and recovery rates.

Cite This Article

APA
Perez Quesada J, Coley K, Wong D, Browne N, Albrecht M, Dembek K. (2026). Biomarkers of brain injury in foals with neonatal maladjustment syndrome. J Vet Intern Med, 40(5), aalag228. https://doi.org/10.1093/jvimsj/aalag228

Publication

Journal of veterinary internal medicine
ISSN: 1939-1676
NlmUniqueID: 8708660
Country: England
Language: English
Volume: 40
Issue: 5
PII: aalag228

Researcher Affiliations

Perez Quesada, Javier
  • Veterinary Associates Equine, Karaka 2580, New Zealand.
Coley, Kinnidy
  • Adoption Center, ASPCA, New York 10128, United States.
Wong, David
  • Department of Clinical Sciences, Iowa State University, Ames 50011, Iowa, United States.
Browne, Nimet
  • Hagyard Equine Medical Institution, 40511 Lexington, United States.
Albrecht, Myriah
  • Hagyard Equine Medical Institution, 40511 Lexington, United States.
Dembek, Katarzyna
  • Department of Clinical Sciences, North Carolina State University, Raleigh 27606, North Carolina, United States.

MeSH Terms

  • Animals
  • Horses
  • Biomarkers / blood
  • S100 Calcium Binding Protein beta Subunit / blood
  • Horse Diseases / blood
  • Animals, Newborn
  • Female
  • Glial Fibrillary Acidic Protein / blood
  • Brain Injuries / veterinary
  • Brain Injuries / blood
  • Brain-Derived Neurotrophic Factor / blood
  • Male
  • Prospective Studies
  • Longitudinal Studies
  • Progesterone / blood

Grant Funding

  • Morris Animal Foundation
  • North Carolina State University

Conflict of Interest Statement

Authors declare no conflicts of interest.

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