Retrospective Evaluation of Neutrophil-to-Lymphocyte Ratio in Horses That Required Emergency Laparotomy: 341 Cases of Noninfectious Causes of Gastrointestinal Colic (2019-2024).
Abstract: To (1) compare total nucleated cell count (TNCC) and neutrophil-to-lymphocyte ratio (NLR) at admission between horses with medically managed, large intestinal (LI) and small intestinal (SI) surgical colic; (2) compare TNCC and NLR between survivors and nonsurvivors; and (3) investigate associations between TNCC, NLR, surgical intervention, and outcome. Methods: Case-control study. Methods: Single, academic institution. Methods: A total of 341 adult horses diagnosed with noninfectious medical or surgical colic. Results: Admission TNCC did not differ between the medical and combined surgical groups, but NLR was higher in the surgical group (3.3 [2-5.2]) compared to the medical group (2.2 [1.6-3.4]). There was no difference in TNCC among the medical, LI, and SI groups, but the SI group's NLR (3.9 [2.8-6.3]) was higher compared to the medical (2.2 [1.6-3.4]) and LI (3.2 [1.6-4.8]) groups. TNCC was not different between survivors and nonsurvivors, but admission NLR was higher in nonsurvivors (3.6 [2-4.8]) compared to survivors (2.7 [1.7-4]). There was no association between admission TNCC and surgical intervention or outcome, but associations were found between NLR and both the need for surgical intervention and outcome. Conclusions: NLR, but not TNCC, at admission is increased in horses with surgical intestinal lesions. Overlap in data precludes its use as a sole marker for case identification, and interpretation of NLR should therefore be performed considering appropriate clinical context. Prospective studies accounting for measurement of adrenocortical hormones are required to investigate NLR changes during the stress response in horses presenting with colic.
© 2025 Wiley Periodicals LLC.
Publication Date: 2025-08-30 PubMed ID: 40884762DOI: 10.1111/vec.70023Google Scholar: Lookup
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- Journal Article
Summary
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Overview
- This study analyzed the neutrophil-to-lymphocyte ratio (NLR) and total nucleated cell count (TNCC) in horses with gastrointestinal colic to assess if these blood parameters can help distinguish between medical and surgical colic cases and predict survival outcomes.
Introduction and Study Objectives
- The research focused on horses experiencing gastrointestinal colic due to noninfectious causes requiring either medical management or emergency surgical intervention (laparotomy).
- Key goals were:
- Compare TNCC and NLR at hospital admission among horses treated medically, those with large intestinal (LI) surgical colic, and those with small intestinal (SI) surgical colic.
- Compare TNCC and NLR between horses that survived and those that did not.
- Determine associations of TNCC and NLR with the need for surgery and overall outcomes.
Methods
- This was a retrospective, case-control study conducted at a single academic institution.
- The sample included 341 adult horses diagnosed with medical or surgical colic from 2019 to 2024.
- Blood samples taken at admission were analyzed for:
- Total nucleated cell count (TNCC)
- Neutrophil-to-lymphocyte ratio (NLR)
- The horses were grouped into:
- Medically managed colic cases
- Surgical colic involving large intestine (LI)
- Surgical colic involving small intestine (SI)
- Survival outcomes were recorded to categorize horses as survivors or nonsurvivors.
Key Findings
- Comparison of TNCC and NLR between medical and surgical groups:
- TNCC did not show significant differences between medical and surgical horses.
- NLR was significantly higher in surgical horses (median 3.3; IQR 2-5.2) compared to medical horses (median 2.2; IQR 1.6-3.4), indicating more inflammation or stress response.
- Comparison among medical, LI surgical, and SI surgical groups:
- TNCC did not differ significantly among the three groups.
- SI surgical horses had the highest NLR (median 3.9; IQR 2.8-6.3), higher than both medical (median 2.2) and LI surgical groups (median 3.2), suggesting more severe inflammatory or stress response in small intestinal lesions.
- Survivors vs. nonsurvivors:
- TNCC was not significantly different between survivors and nonsurvivors.
- NLR was higher on admission in nonsurvivors (median 3.6; IQR 2-4.8) compared to survivors (median 2.7; IQR 1.7-4), implying that a higher NLR may be associated with worse prognosis.
- Associations between TNCC, NLR, surgery, and outcomes:
- No significant association between admission TNCC and either the need for surgical intervention or survival outcome was found.
- Significant associations existed between admission NLR and both the likelihood of requiring surgery and survival outcomes, although the overlap in data limits its use as a sole diagnostic marker.
Conclusions and Implications
- The NLR measured at hospital admission is elevated in horses with surgical intestinal lesions compared to medically managed cases, especially those involving the small intestine.
- Because there is overlap in NLR values between different groups, it cannot be used alone to definitively identify horses requiring surgery or predict outcome.
- TNCC was not a helpful parameter for differentiating colic type or predicting survival in this study.
- Interpretation of NLR should be combined with clinical findings and other diagnostic information.
- Future prospective studies should explore how stress hormones, such as adrenocortical hormones, influence NLR changes during colic episodes to better understand the physiological response.
Cite This Article
APA
Migliorisi A, Nottle B, Smanik LE, Nout-Lomas YS, Hassel DM.
(2025).
Retrospective Evaluation of Neutrophil-to-Lymphocyte Ratio in Horses That Required Emergency Laparotomy: 341 Cases of Noninfectious Causes of Gastrointestinal Colic (2019-2024).
J Vet Emerg Crit Care (San Antonio), 35(4), 378-385.
https://doi.org/10.1111/vec.70023 Publication
Researcher Affiliations
- Department of Clinical Sciences, College of Veterinary Medicine and Biomedical Sciences, Colorado State University, Fort Collins, Colorado, USA.
- Department of Clinical Sciences, College of Veterinary Medicine and Biomedical Sciences, Colorado State University, Fort Collins, Colorado, USA.
- Department of Clinical Sciences, College of Veterinary Medicine and Biomedical Sciences, Colorado State University, Fort Collins, Colorado, USA.
- Department of Clinical Sciences, College of Veterinary Medicine and Biomedical Sciences, Colorado State University, Fort Collins, Colorado, USA.
- Department of Clinical Sciences, College of Veterinary Medicine and Biomedical Sciences, Colorado State University, Fort Collins, Colorado, USA.
MeSH Terms
- Animals
- Horses
- Horse Diseases / surgery
- Horse Diseases / blood
- Colic / veterinary
- Colic / surgery
- Colic / blood
- Neutrophils
- Case-Control Studies
- Retrospective Studies
- Male
- Lymphocytes
- Female
- Laparotomy / veterinary
- Leukocyte Count / veterinary
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