Transcript Venipuncture and Clinical Pathology for Reptiles

Venipuncture and Clinical
Pathology for Reptiles
Introduction
► Reptiles
 stoic
 evolved to mask illness
► Treat
n’ run?
► Diagnostic Tests
 to identify physiologic
anomalies
Weight the reptile first
Blood Collection
►Blood
volume:
 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 overfillmicroclots
► 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
►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
large
pool very
 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 metachromatic 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
► 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, nonlactated, 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?