Evaluation of peritoneal L-lactate concentration in horses in the early post-partum period

Rapezzano, Giulia; Marcatili, Marco; Stephenson, Richard; Pereira, Regina; Hallowell, Gayle; Duz, Marco

Abstract

Background: Peritoneal fluid lactate concentration is an important diagnostic tool in horses with abdominal pain. Information on peritoneal lactate concentrations is lacking following parturition in the mare.

Objectives: To compare blood and peritoneal lactate concentrations in a population of mares within 36 h post‐partum, report a normal reference range and identify any impact of retained foetal membranes (RFMs).

Methods: This is a retrospective study evaluating healthy mares from which blood and peritoneal samples had been obtained within 36 h of parturition. Exclusion criteria included signs of abdominal pain within this period. Data was interrogated for normality using a Shapiro–Wilk test. Wilcoxon signed‐rank test and Bland–Altman analysis were used to compare blood and peritoneal lactate concentrations. Linear regression was used to compare age and breed data with peritoneal lactate concentrations. Significance was defined as p < 0.05.

Results: Forty mares met the inclusion criteria. Mean age was 12.6 ± 4.1 years, and most mares were multiparous (65%). Peritoneal lactate ((1.2 (IQR = 0.9–1.6) mmol/L) was increased compared to blood lactate concentration (0.7 (IQR = 0–1.1)mmol/L; p < 0.001). Plasma total protein (TP) concentrations were 68 (IQR = 64–74) g/L and peritoneal protein concentrations 8 (IQR = 4–9.7) g/L. Six mares developed RFM. The median fold‐increase in peritoneal lactate concentration compared to blood lactate concentration was 0.9 (IQR: 0.01–1.7; range: 0–2.5). The reference range for peritoneal fluid lactate concentration was 0–2.5 mmol/L.

Conclusion: Peritoneal lactate concentrations in healthy post‐partum mares remained within the normal reference range and were not influenced by RFM or parturition. Increased peritoneal lactate in this group warrants further investigation.

Citation

Rapezzano, G., Marcatili, M., Stephenson, R., Pereira, R., Hallowell, G., & Duz, M. (2024). Evaluation of peritoneal L-lactate concentration in horses in the early post-partum period. Veterinary Medicine and Science, 10(3), Article e1352. https://doi.org/10.1002/vms3.1352

• Journal Article Type: Article
• Acceptance Date: Jan 5, 2024
• Online Publication Date: Apr 17, 2024
• Publication Date: 2024-05
• Deposit Date: Mar 26, 2025
• Publicly Available Date: Mar 31, 2025
• Journal: Veterinary Medicine and Science
• Electronic ISSN: 2053-1095
• Publisher: Wiley Open Access
• Peer Reviewed: Peer Reviewed
• Volume: 10
• Issue: 3
• Article Number: e1352
• DOI: https://doi.org/10.1002/vms3.1352
• Keywords: mare, lactate, foaling, clinical pathology, abdominocentesis, equine
• Public URL: https://nottingham-repository.worktribe.com/output/34093418
• Publisher URL: https://onlinelibrary.wiley.com/doi/10.1002/vms3.1352