Abstract

Lymph contamination of peripheral blood samples is common in reptile clinical practice due to a close association of the lymphatic and vascular systems. Grossly lymph-contaminated samples are generally discarded due to potential dilution effects on hematologic and biochemistry parameters. Differences in biochemistry values from different sample sites in chelonians are often attributed to lymph contamination.^2,3 Previous studies have evaluated blood-lymph mixtures but provide limited information since the proportion of lymph is unknown.¹ Differences in biochemistry values of pure lymph compared to plasma are unknown in chelonian species. Paired plasma samples collected from the jugular vein and lymph samples collected from the dorsal lymphatic ring adjacent to the subcarapacial sinus were collected from 11 (six females, five males) Krefft’s river turtles (Emydura macquarii krefftii) for comparison of biochemistry analytes. No significant differences were found between lymph and plasma samples for chloride, glucose, alanine transaminase, aspartate transaminase, creatinine kinase, urea nitrogen, and total bilirubin. Statistically significant (p<0.05) differences were found between lymph and plasma samples for gamma glutamyl transferase, total protein, globulin, and uric acid. Sex and sample differences were statistically significant for sodium, potassium, calcium, phosphorous, magnesium, lactate dehydrogenase, albumin, and triglycerides, while significant sex differences only were found for alkaline phosphatase, cholesterol, and iron. For most sex differences, values for females were greater than for males. For most sample differences, values for plasma were greater than for lymph; therefore, lymph contamination of plasma samples may affect clinical diagnostic interpretation.

Acknowledgments

The authors thank Dr. Kyle Donnelly and the Department of Animal Programs at Brevard Zoo for their help with this study.

Literature Cited

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3.  López-Olvera JR, Montané J, Marco I, Martínez-Silvestre A, Soler J, Lavin S. Effect of venipuncture site on hematologic and serum biochemical parameters in marginated tortoise (Testudo marginata). J Wildl Dis. 2003;39(4):830–836.