Hematology, leukocyte cytochemical analysis, plasma biochemistry, and plasma electrophoresis of wild-caught and captive-bred Gila monsters (Heloderma suspectum)

Background: The Gila monster (Heloderma suspectum), one of several venomous lizard species in the world, is found within the United States and Mexico and is recognized as an iconic symbol of the American Southwest. Thus, Gila monsters are of growing interest in the captive reptile trade and within zoological and educational institutions. Objectives: The aims of this study were to determine results for CBCs, describe cytochemical reactions in WBCs, and obtain plasma biochemical and protein electrophoresis results from wild-caught and captive-bred H. suspectum. Methods: Ventral tail vein blood samples were obtained from 16 captive (14 wild-caught and 2 captive-bred) Gila monsters. CBCs, RBC morphometric analysis, plasma biochemical analysis, and protein electrophoresis were performed. Leukocytes were stained for peroxidase, Sudan black B (SBB), chloroacetate esterase, napthyl butyrate esterase, and leukocyte alkaline phosphatase, and blood smears were examined for the presence of hemoparasites. Results: The median (range) PCV was 37% (22-50%) and WBC count was 4.6 × 10 ³/μL (3.3-6.4 × 10 ³/μL) with approximately 50% heterophils and fewer lymphocytes, basophils, azurophils, and monocytes in decreasing order. Cytochemical reactions were unique among reptiles with strong staining for peroxidase and SBB in monocytes/azurophils. Biochemical results were similar to those of earlier reports with slight increases in uric acid and urea concentrations. Plasma electrophoretic results indicated that albumin was approximately equal to the combined globulin fractions. Conclusions: Results of blood analysis in healthy wild-caught and captive-bred H. suspectum may be useful for monitoring health status in this species.