Analyze Diet

Interpreting abdominal fluid in colic horses: Understanding and applying peritoneal fluid evidence.

Abstract: Interpreting changes in peritoneal fluid helps clinicians manage colic and other diseases in horses. During abdominal problems in the horse, abdominal fluid characteristics such as color, turbidity, total nucleated and red blood cell counts, cytology, total protein, and l-lactate change in predictable ways, helping the clinician characterize the disease. Methods: Normal abdominal fluid in horses is odorless, clear to light yellow in color, and transparent. Peritoneal fluid becomes more turbid with increasing levels of protein, number of WBCs or RBCs, or with gross contamination following intestinal rupture. The color of abdominal fluid will also change with the type and quantity of cells or other elements present. The transformation of peritoneal fluid color from golden to orange to red represents increasing levels of RBCs, common with strangulating intestinal lesions. Serosanguinous defines fluid that is both turbid and orange to bloody because of increased total protein, WBCs, and RBCs, and is considered classic for diseases characterized by intestinal ischemia. Peritoneal fluid may also be red or blood-colored because of a hemoperitoneum, or secondary to blood contamination during sample collection. l-Lactate measurement in the abdominal fluid has proven invaluable for the identification of strangulating intestinal injury. Cytology acts as an important supplement to cell counts in peritoneal fluid, and the normal ratio of non-degenerate neutrophils:mononuclear cells of 2:1 changes during various gastrointestinal diseases. Culture of peritoneal fluid samples should be performed when septic peritonitis is suspected. Conclusions: Abdominal fluid is a sensitive indicator of intestinal injury and a useful tool to direct treatment. Peritoneal fluid evaluation includes gross visual and olfactory examination, nucleated cell count, total protein, RBC count, lactate levels, cytology, and culture. The changes noted in such variables are related to the type and duration of the abdominal problem. Conclusions:  Abdominal fluid interpretation has become central to the triage and management of challenging equine colic patients.  The transformation of peritoneal fluid color from golden to orange to red represents increasing levels of RBCs, common with strangulating intestinal lesions.  Contamination with RBCs at various concentrations may be secondary to vascular (eg, abdominal wall or mesenteric vessels) or splenic trauma during abdominal fluid collection; however, this must be distinguished from orange to red fluid associated with intestinal strangulating obstruction or hemoabdomen  Peritoneal fluid analysis reveals abdominal pathology by recognizing specific changes that occur with disease processes affecting the tissues and organs within this cavity.  Abdominal fluid examination should be used as a tool to direct treatment rather than the definitive test for diagnosis of the acute abdomen  Septic peritonitis in horses most commonly originates secondary to intestinal compromise or accidents (vascular damage, perforation, or surgical manipulation), leading to bacterial translocation into the abdomen.
Publication Date: 2022-01-20 PubMed ID: 35044063DOI: 10.1111/vec.13117Google Scholar: Lookup
The Equine Research Bank provides access to a large database of publicly available scientific literature. Inclusion in the Research Bank does not imply endorsement of study methods or findings by Mad Barn.
  • 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.

The research article discusses the crucial role that interpreting changes in peritoneal fluid (abdominal fluid) plays in managing colic and other diseases in horses, especially with respect to identifying and treating severe intestinal injuries.

Content of the Study

  • The study begins by examining the predictable changes in characteristics such as color, turbidity, total nucleated and red blood cell counts, cytology, total protein, and l-lactate levels of abdominal fluid when a horse develops abdominal problems.
  • The paper describes normal abdominal fluid as being odorless, clear to light yellow in color, and transparent. These characteristics, however, change in predictable ways when horses encounter issues such as colic.
  • The article mentions that the fluid becomes more turbid with increasing levels of protein, number of white and red blood cells (WBCs and RBCs), or gross contamination due to intestinal rupture. These changes indicate the nature and severity of the disease involved.

Changes in Abdominal Fluid

  • The transformation of peritoneal fluid color from golden to orange to red represents increasing levels of RBCs, which is common in horses with strangulating intestinal lesions.
  • Likewise, fluid that is both turbid and orange to bloody is termed as ‘serosanguinous,’ and usually indicates diseases characterized by intestinal ischemia.
  • The article points out that peritoneal fluid may also be red or blood-colored due to a hemoperitoneum, or secondary to blood contamination during sample collection.

Measures in Abdominal Fluid

  • The document highlights the importance of measuring l-Lactate levels in the peritoneal fluid for the identification of strangulating intestinal injury.
  • It denotes cytology as a supplement to cell counts in abdominal fluid, noting that the normal ratio of non-degenerate neutrophils to mononuclear cells changes with various gastrointestinal diseases.
  • The authors recommend performing a culture of peritoneal fluid samples when a horse is suspected to have septic peritonitis, a dangerous condition often caused by bacterial translocation into the abdomen due to intestinal compromise or accidents.

Conclusion of the Study

  • The paper concludes by defining abdominal fluid as a sensitive indicator of intestinal injury and thus, a crucial tool for directing the treatment of equine patients suffering from abdominal issues.
  • These conclusions underscore the need for regular evaluation of peritoneal fluid to improve the diagnosis and treatment outcomes of equine abdominal diseases.

Cite This Article

APA
Radcliffe RM, Liu SY, Cook VL, Hurcombe SDA, Divers TJ. (2022). Interpreting abdominal fluid in colic horses: Understanding and applying peritoneal fluid evidence. J Vet Emerg Crit Care (San Antonio), 32(S1), 81-96. https://doi.org/10.1111/vec.13117

Publication

ISSN: 1476-4431
NlmUniqueID: 101152804
Country: United States
Language: English
Volume: 32
Issue: S1
Pages: 81-96

Researcher Affiliations

Radcliffe, Rolfe M
  • Department of Clinical Sciences, College of Veterinary Medicine, Cornell University, Ithaca, New York, USA.
Liu, Sharon Y
  • Department of Clinical Sciences, College of Veterinary Medicine, Cornell University, Ithaca, New York, USA.
Cook, Vanessa L
  • Emergency Surgery and Medicine, Cornell Ruffian Equine Specialists, Elmont, New York, USA.
Hurcombe, Samuel D A
  • Department of Large Animal Clinical Sciences, College of Veterinary Medicine, Michigan State University, East Lansing, Michigan, USA.
Divers, Thomas J
  • Department of Clinical Sciences, College of Veterinary Medicine, Cornell University, Ithaca, New York, USA.

MeSH Terms

  • Animals
  • Ascitic Fluid
  • Colic / diagnosis
  • Colic / veterinary
  • Horse Diseases / diagnosis
  • Horses
  • Intestinal Obstruction / veterinary
  • Peritonitis / veterinary

References

This article includes 22 references
  1. White NA II. Determining the diagnosis and prognosis of the acute abdomen. The Equine Acute Abdomen. 1st ed. Malvern: Lea & Febiger; 1990, pp. 101-147.
  2. Mair T. Abdominocentesis (abdominal paracentesis). In: Mair TS, Divers TJ, Ducharme NG, eds. Manual of Equine Gastroenterology. 1st ed. St. Louis: WB Saunders. 2002, pp. 13-20.
  3. Dallap Schaer B, Orsini JA. Gastrointestinal system. In: Orsini JA, Divers TJ, eds. Equine Emergencies: Treatment and Procedures. 4th ed. St. Louis: Elsevier; 2014, pp. 157-237.
  4. Hunt E, Tennant BC, Whitlock RH. Interpretation of peritoneal fluid erythrocyte counts in horses with abdominal disease. Proc Eq Colic Res Symp 1986; 2:168-174.
  5. Stokol T. Cytology. In: Orsini JA, Divers TJ, eds. Equine Emergencies: Treatment and Procedures. 4th ed. St. Louis: Elsevier; 2014, pp. 37-60.
  6. Malark JA, Peyton LC, Galvin MJ. Effects of blood contamination on equine peritoneal fluid analysis. J Am Vet Med Assoc 1992; 201(10):1545-1548.
  7. Radcliffe RM, Buchanan BR, Cook VL, Divers TJ. Whole blood point of care biomarkers review: clinical value in large animal emergency critical care. J Vet Emerg Crit Care 2015; 25(1):138-151.
  8. Latson KM, Nieto JE, Beldomenico PM, Snyder JR. Evaluation of peritoneal fluid lactate as a marker of intestinal ischemia in equine colic. Equine Vet J 2005; 37(4):342-346.
  9. Dickinson C. Peritonitis. In: Reed SM, Bayly WM, Sellon DC, eds. Equine Internal Medicine. 2nd ed. St. Louis: Elsevier; 2004, pp. 941-949.
  10. Van Hoogmoed L, Roger LD, Spier SJ, Gardner IA, Yarbrough TB, Snyder JR. Evaluation of peritoneal fluid pH, glucose concentration, and lactate dehydrogenase activity for detection of septic peritonitis in horses. J Am Vet Med Assoc 1999; 214(7):1032-1036.
  11. Schumacher J, Spano JS, Moll HD. Effects of enterocentesis on peritoneal fluid constituents in the horse. J Am Vet Med Assoc 1985; 186(12):1301-1303.
  12. Matthews S, Dart AJ, Reid SWJ, Dowling BA, Hodgson DR. Predictive values, sensitivity and specificity of abdominal fluid variables in determining the need for surgery in horses with an acute abdominal crisis. Aust Vet J 2002; 80(3):132-136.
  13. Peloso JG, Cohen ND. Use of serial measurements of peritoneal fluid lactate concentration to identify strangulating intestinal lesions in referred horses with signs of colic. J Am Vet Med Assoc 2012; 240(10):1208-1217.
  14. Delesalle C, Dewulf J, Lefebvre RA. Determination of lactate concentrations in blood plasma and peritoneal fluid in horses with colic by an Accusport analyzer. J Vet Intern Med 2007; 21(2):293-301.
  15. Johnston K, Holcombe SJ, Hauptman JG. Plasma lactate as a predictor of colonic viability and survival after 360° volvulus of the ascending colon in horses. Vet Surg 2007; 36(6):563-567.
  16. Tennent-Brown BS, Wilkins PA, Lindborg S, Russell G, Boston RC. Sequential plasma lactate concentrations as prognostic indicators in adult equine emergencies. J Vet Intern Med 2010; 24(1):198-205.
  17. Barton MH, Collatos C. Tumor necrosis factor and interleukin-6 activity and endotoxin concentration in peritoneal fluid and blood of horses with acute abdominal disease. J Vet Intern Med 1999; 13(5):457-464.
  18. Weimann CD, Thoefner MB, Jensen AL. Spectrophotometric assessment of peritoneal fluid haemoglobin in colic horses: an aid to selecting medical vs. surgical treatment. Equine Vet J 2002; 34(5):523-527.
  19. Saulez MN, Cebra CK, Tornquist SJ. The diagnostic and prognostic value of alkaline phosphatase activity in serum and peritoneal fluid from horses with acute colic. J Vet Intern Med 2004; 18(4):564-567.
  20. Pihl TH, Scheepers E, Sanz M. Influence of disease process and duration on acute phase proteins in serum and peritoneal fluid of horses with colic. J Vet Intern Med 2015; 29(2):651-658.
  21. Pihl TH, Scheepers E, Sanz M. Acute-phase proteins as diagnostic markers in horses with colic. J Vet Emerg Crit Care 2016; 26(5):664-674.
  22. Pihl TH, Andersen PH, Kjelgaard-Hansen M, Mørck NB, Jacobsen S. Serum amyloid A and haptoglobin concentrations in serum and peritoneal fluid of healthy horses and horses with acute abdominal pain. Vet Clin Pathol 2013; 42(2):177-183.

Citations

This article has been cited 7 times.
  1. Fikri F, Hendrawan D, Wicaksono AP, Purnomo A, Khairani S, Chhetri S, Maslamama ST, Purnama MTE. Incidence, risk factors, and therapeutic management of equine colic in Lamongan, Indonesia. Vet World 2023;16(7):1408-1414.
  2. Nocera I, Cingottini D, Di Franco C, Sala G, Bindi F, Spadari A, Rinnovati R, Vitale V, Jose-Cunilleras E, Sgorbini M. In-Depth Analysis of the Prognostic Factors Associated with Short-Term Outcome in Equine Colic Patients: Multicentric Retrospective Study. Animals (Basel) 2026 Feb 5;16(3).
    doi: 10.3390/ani16030496pubmed: 41681477google scholar: lookup
  3. Parra-Moyano LA, Cedeño A, Darby S, Johnson JP, Gomez DE. Blood and Peritoneal Lactate, Ratio and Difference, and Peritoneal Lactate to Total Solids Ratio for Detection of Intestinal Strangulating Obstructions in Horses. J Vet Intern Med 2025 Jul-Aug;39(4):e70121.
    doi: 10.1111/jvim.70121pubmed: 40448701google scholar: lookup
  4. Tharwat M, Al-Sobayil F. Equine colic: A comprehensive overview of the sonographic evaluation, diagnostic criteria, and management of different categories. Open Vet J 2025 Mar;15(3):1116-1139.
    doi: 10.5455/OVJ.2025.v15.i3.5pubmed: 40276205google scholar: lookup
  5. Martin E, Sarkan K, Viall A, Hostetter S, Epstein K. Clinicopathologic Parameters of Peritoneal Fluid as Predictors of Gastrointestinal Lesions, Complications, and Outcomes in Equine Colic Patients: A Retrospective Study. Animals (Basel) 2024 Dec 24;15(1).
    doi: 10.3390/ani15010012pubmed: 39794955google scholar: lookup
  6. Viterbo L, Hughes J, Milner PI, Bardell D. Arterial Blood Gas, Electrolyte and Acid-Base Values as Diagnostic and Prognostic Indicators in Equine Colic. Animals (Basel) 2023 Oct 17;13(20).
    doi: 10.3390/ani13203241pubmed: 37893965google scholar: lookup
  7. Birckhead EM, Das S, Tidd N, Raidal SL, Raidal SR. Visualizing neutrophil extracellular traps in septic equine synovial and peritoneal fluid samples using immunofluorescence microscopy. J Vet Diagn Invest 2023 Nov;35(6):751-760.
    doi: 10.1177/10406387231196552pubmed: 37661696google scholar: lookup