Reference values of peritoneal fluid from healthy foals

Abstract

Summary Thirty-two clinically healthy Thoroughbred foals, aged 14 to 75 days (x=45.5 days), were used to evaluate several parameters in peritoneal fluid. The evaluation revealed clear, pale yellow fluid with a mean total protein concentration of 1.8 gm/dl ± 0.7 (x±SD). The mean total of nucleated cell count was 1,418/ul ± 1,077, which was distributed as follows: neutrophils 15.3% ± 20.4, large mononuclear cells 43.8% ± 24.8, small mononuclear cells 22.3% ± 24.5. Eosinophils were not observed in any sample and the erythrocyte count was 12,070/ul ± 15,219. Nine different biochemical parameters were determined in paired samples of peritoneal fluid (PF) and serum. Results of the biochemical analysis of PF were : glucose 136.9 mg/dl ± 21, aspartate aminotransferase (AST) 50 IU/L ± 18.9, alkaline phosphatase 43.6 IU/L ± 15.15, lactate dehydrogenase (LDH) 46.5 IU/L ± 22.9, creatinine 1.39 mg/dl ± 0.22, sodium 133.6 mEq/L ± 2.18, chloride 98.7 mEq/L ± 4.16, potassium 4.2 mEq/L ± 0.36 and fibrinogen A valuable aid for determining the probable cause of abdominal pain is analysis of peritoneal fluid (PF). Analysis of peritoneal fluid is helpful in assessing other abdominal conditions such as chronic diarrhea, parasitic larvals migrans, abdominal abscessation, granulomatous enteritis and metastatic gastric squamous cell carcinoma. This ancillary aid is even more important for foals because rectal palpation is impossible due to their small size. Abdominocentesis of the horse was described more than 30 years ago 22 and is now a routine procedure for evaluation of horses with abdominal distress. Evaluation of PF from horses with acute abdominal conditions is well documented; 4 , 5 , 8 , 9 , 20 , 24 , 26 – 28 , 38 41 however, most of the literature deals with adult horses. Although the field of equine neonatology has been recently advancing, 30 we were not able to find studies of analysis of PF from healthy foals. The serum and PF concentrations of aspartate transaminase (AST), 19 alkaline phosphatase (ALP), 13 , 16 , 37 and lactate dehydrogenase (LDH), 40 as well as the concentrations of lactic acid, 25 fibronectin, 14 and phosphate 3 have been reported. The aim of those determinations was to search for an accurate index to predict early compromise of bowel; however, the sensitivity and specificity have been variable. 29 The purposes of this study were: 1) to report reference values for PF from healthy foals, 2) to report values of different biochemical parameters evaluated in paired samples of serum and PF and 3) to determine the relationship of those parameters between serum and PF.