Common Reptile Diagnostics Flashcards
(97 cards)
What would be the safe volume of blood to take from the following reptiles?
- Nagini, 3 y/o FI, 60 g
- Lizzie, 6 y/o FI, 2 kg
total safe amount is 1% of BW in grams
- .01 x 60g = 0.6 mL
- .01 x 200g = 20 mL
What are the preferred blood collection sites for chelonians, snakes, lizards, and crocodilians?
CHELONIANS - subcarapacial sinus, jugular, coccygeal, brachial plexus
SNAKES - cardiocentesis, palatine, ventral coccygeal
LIZARDS - ventral coccygeal, ventral abdominal, jugular
CROCODILIANS - post-occipital sinus, coccygeal;
What should be done once blood is successfully obtained from a reptile? What is the anticoagulant of choice?
blood smear
heparin
What 2 erythrocyte parameters are for reptile bloodwork?
- PCV - 20-45%, within (heparinized) microhematocrit tubes
- RBC - reptile automated cell counter, manual hemocytometer + staining/dilution
What are the main 2 options for staining/diluting RBCs for manual counting on a hemocytometer?
- Eopette/Leukopette (Phloxine B) - only stains granulocytes
- Natt-Herricks solution - can differentiate RBCs (small lymphocyte) and WBCs (thrombocyte)
Hemocytometer:
What is the normal morphology of reptile RBCs? How do immature ones compare to mature ones?
oval with an irregularly marginated nucleus
immature RBCs are smaller, rounder, and have basophilic stippling
What are 3 locations that new RBCs are produced in reptiles?
- BM
- extramedullary = liver, spleen
- mature circulating cells divide and form daughter cells (will have mitotic figures)
How can reticulocytes be observed on a blood smear? How much of the RBC should they take?
new methylene blue
2.5% or less
How are WBCs measured in reptiles?
different morphologies compared to mammals and cannot use an automated counter —> manual counts on blood smears stained with Romanowski or Wright-Giesma
RBCs and WBCs:
- large arrowhead = lymphocyte
- asterisk = thrombocyte
- arrow = azurophil
What is the most common granulocyte in reptiles? What are the 2 major aspects of its morphology?
heterophil - analogous to neutrophils
- round, clear cytoplasm
- eosinophilic, elongated/spindle-shaped granules
What are 4 indications of toxic heterophils? What does this mean?
- basophilic cytoplasm
- abnormal granules
- vacuoles
- degranulation
a way to monitor chronic disease processes
What are the 2 major morphological aspects of eosinophils? What species lack them?
- similar in size and shape to heterophils with an eccentric nucleus
- spherical (red) granules —> “gumballs”
What WBC is seen in this blood smear?
green iguana eosinophil
What are the 2 major morphological aspects of basophils? What must they be differentiated from?
- smaller
- darkly basophilic granules obscure central, nonlobed nucleus
toxic heterophils
What are the 5 major morphological aspects of lymphocytes?
- lack granules
- high nucleus:cytoplasm ratio
- basophilic cytoplasm
- phagocytosed particles or RBCs can be seen in cytoplasm
- contour to surrounding cells
What do reactive lymphocytes indicate? What is their morphology like?
antigenic stimulation
- basophilic cytoplasm
- contain discrete punctate vacuoles
What is the morphology of monocytes like?
largest leukocyte with variably shaped contour and nucleus
What is a common variation of monocytes in reptiles? How do they compare in species?
azurophils
- non-squamates = normal variation of monocytes containing azurophilic granules
- snakes = distinct cell type that function similarly to neutrophils and contain fine granules and round nuclei
Label the cells seen in this blood smear.
- arrow with long arrowhead = monocyte/azurophil
- normal arrow = heterophil
- large arrowhead = lymphocyte (low cytoplasm!)
- skinny arrow with large arrowhead = eosinophil
- asterisks = RBC
Label the cells seen in this blood smear from a snake.
- large arrowhead = lymphocyte (low cytoplasm!)
- asterisk = thrombocyte
- normal arrow = azurophil (darker, large cytoplasm, small nucleus)
What are the 3 major morphologic aspects of thrombocytes?
- small, oval basophilic cells
- central basophilic nucleus
- pale-blue or colorless cytoplasm
(*)
Label the cells seen in this blood smear.
- arrowhead = eosinophil
- long arrow with large arrowhead = monocyte (large cell!)
- 2 normal arrows = heterophils
- asterisks = thrombocytes