Reference values for hematology and plasma biochemistry variables, and protein electrophoresis of healthy Hermann's tortoises (Testudo hermanni ssp.)

Abstract

Background: Hermann's tortoise, Testudo hermanni, is currently on the International Union for Conservation of Nature (IUCN) red list of endangered species. Reptile medicine relies also on laboratory analyses to evaluate health status, but reference ranges for hematology and biochemistry variables and protein electrophoresis in plasma of healthy tortoises are not available.

Objective: The purposes of this study were to establish reference ranges for select hematologic and biochemical variables in clinically healthy Hermann's tortoises, and evaluate the impact of sex and season.

Methods: Blood samples were collected from 34 healthy tortoises at the end of September and beginning of July. Blood smears, HCT, concentrations of HGB and select plasma biochemical analytes, select enzyme activities, and plasma protein fractions were evaluated. Reference ranges were determined and checked for influence of sex and sampling time point.

Results: Typical reptilian RBC and WBC were observed in blood smears. HCT and concentrations of HGB, uric acid and urea, and ALT and AST activities were significantly higher in males than in females. Concentrations of glucose, uric acid, and phosphate, and AST activity were significantly higher at the beginning of July, whereas concentrations of urea and Cl were higher at the end of September prior to hibernation. The electrophoretic protein fractions included albumin, and α, β, and γ globulins.

Conclusions: The reference ranges defined in the present study are useful for clinical tortoise medicine and conservation. Sex and seasonal sampling were identified as factors significantly affecting hematology and blood chemistry analytes; they should be taken into consideration when assessing tortoise health status.

Keywords: Blood cells; health assessment; normal values; reptile conservation; reptile medicine.