Peritoneal fluid values from healthy foals.

The research article analyses the peritoneal fluid from healthy foals to determine what values should be considered normal or elevated. The information gathered indicates that certain adult horse reference values may not be applicable for foals and that a different set of criteria may need to be implemented for diagnostic purposes.

Study Group and Methodology

• The study included 17 healthy foals ranging in age from 13 to 134 days, and the mean age was 68 days.
• The peritoneal fluid from these foals was collected and analyzed.

Analysis of Peritoneal Fluid

• The cytological examination of the fluid revealed a mean total cell count of 0.45 x 10⁹/litre, rare instances of eosinophils and cytophagia, and variable percentages of neutrophils and mononuclear cells.
• From these data, it was determined that peritoneal fluid nucleated cell counts over 1.50 x 10⁹/litre in the foal should be considered elevated.

Biochemical Evaluation

• Further biochemical evaluation of the fluid showed a mean biuret protein level of 12 g/litre, mean refractive index protein level of 16 g/litre, and urea nitrogen concentration of 1.96 mmol/litre.
• There was no correlation found between the white blood cell count of the foals and the peritoneal fluid nucleated cell count.

Comparison to Adult Horse Values

• The researchers concluded that adult horse reference values, which are typically used for evaluation of peritoneal fluid, are of questionable validity when applied to foals.
• Notably, they found that maximum peritoneal fluid nucleated cell counts in healthy foals were significantly lower than the reported maximal reference values for adult horses (1.5 x 10⁹/litre versus 5.0 x 10⁹/litre or 10.0 x 10⁹/litre, respectively).

Implications and Conclusions

• This result implies that the diagnostic criteria used to interpret the health of adult horses may not be suitable for foals, and researchers suggest a reassessment of the reference values for peritoneal fluid in foals is necessary.