Venipuncture and Clinical Pathology for Reptiles

Introduction Reptiles Treat n’ run? Diagnostic Tests stoic evolved to mask illness Treat n’ run? Diagnostic Tests to identify physiologic anomalies

Weight the reptile first

Blood Collection Blood volume: General rule of thumb: 5-8% of body weight reptiles Tolerate 1% loss General rule of thumb: 0.5-0.8 ml/100 g (reptiles) To heparinize or not to heparinize? Consider time to collect LIMIT VOLUME OF HEPARIN May affect cell staining

Venipuncture sites: Lizards Ventral coccygeal/tail vein Ventral abdominal vein Jugular Cardiac- euthanasia Toe nail

Venipuncture sites: Snakes Cardiac Ventral tail vein

Venipuncture sites: Chelonians Jugular Dorsal coccygeal Brachial Subcarapacial

Subcarapacial

Venipuncture sites: Crocodilians Ventral tail Ventral abdominal Cardiac Supravertebral

Blood collection tubes: Ethylene diamine tetra acetic acid CBC and plasma chemistry use microtainers less likely to dilute sample do not overfill- microclots disadvantages: hemolyzes RBC’s: especially tortoises elevated potassium* decreased calcium*

Blood collection tubes: Lithium heparin CBC or plasma chemistries less damaging to cells centrifuge immediately cells will consume glucose potassium and phosphorus increase from leakage

Blood collection tubes: No anticoagulant Red top tube centrifuge to collect serum serum may form gelatinous clot may lose sample continue to centrifuge, may help more common in glass tubes microtainer: plastic

Hematology Evaluating the packed cell volume Reference ranges: 20-40% (reptile) 40-55% (avian) 30-55% (mammalian; ferret 45-58%) Buffy coat: anecdotal used to estimate WBC (mammals) limited samples suggest not useful Lawton and Divers, 1999 Serum appearance

Hematology: Total Red Blood Cell Count Manual techniques: Erythrocyte Unopette system Erythrocytes mature cells ellipsoid with central nucleus cytoplasm- orange-pink immature cells small, round cells basophilic cytoplasm

Hematology Erythrocytes abnormal shapes and sizes basophilic stippling regeneration basophilic stippling anemia, iron deficiency hypochromatosis- iron deficiency anemia, chronic blood loss

Hematology Blood parasites common wild caught specimens evaluate overall health anemia? regenerative

Hematology: Leukocytes Circulating pool very large reference ranges 5.0-15.0 x 103

Hematology: Granulocytes Heterophils fusiform granules large round, acentric nucleus function- phagocytosis heterophilia inflammation, stress seasonal increase summer

Hematology: Granulocytes Toxic heterophils suggestive of infectious cause indicative of severity changes degranulation cell swelling cytoplasmic vacuolization

Hematology : Granulocytes Eosinophil large, round cells spherical granules nucleus centrally located function- Parasitemia Allergy Inflammation seasonal variation increased winter

Hematology : Granulocytes Basophils small, spherical cells basophilic meta-chromatic granules function histamine release

Hematology: Lymphocyte Lymphocytes small, basophilic staining acentric nucleus function B cells- Ab production T cells moderate immune function seasonal variation decreased in winter

Hematology: Monocyte Azurophil Largest WBC cytoplasm- blue-gray function granuloma formation

Hematology Thrombocytes central nucleus confused with lymphocytes functions- thrombus formation, clot, wound healing >200,000 cells/ml

Injections Page 110 L, 159 S, 177 T Demonstration

Fluid Support Ideal fluid is hypotonic, non-lactated, balanced electrolyte (e.g. Normosol R) Maintenance fluids can be calculated at 20 ml.kg.day.

Fluid Support SQ, ICe, IV, IO, PO are all effective, choice of route depends on severity of illness and logistics of individual animals Always inject between scales Liquid enteral nutrition (e.g. Ensure, Sustacal, useful for recovery from long-term anorexia, may be mixed with vegetables or fruits for herbivores) Critical Care Herbivore Diet by Oxbow Hay Co. or enterals from Walkabout Farms

Fluid Support Pharyngostomy tubes may be needed for some chelonians Force feeding, assist feeding

Force feeding demo.

Radiology Lateral, DV, AP Horizontal beam if possible Consider mammography or dental film GI contrast IVP- recently described, usefulness needs to be determined. Page 110 L, 150 S, 175 T

Chelonians Whole-body Craniocaudal view

Venomous snake

Questions?