Exotic Hematology

Question 1

challenges of obtaining exotic blood

Answer 1

we usually can only get smaller blood samples: may not be able to redraw, redraws could cause more potential danger to patient
sicker animals means we should draw less blood
blood is more delicate in exotics

Question 2

stains for exotic blood

Answer 2

Romanowsky-type: Wrights and Wrights-Giemsa- long and fussy, high quality results
May Grunwald- similar to Wrights
Diff Quick- usually have in-house, fast and easy to use, inexpensive

Question 3

sample handling

Answer 3

use smaller syringes/needles: 27G, 26G, insulin syringes
use microtainers since we usually get a small sample
consider best venipuncture site: what is most practical, less stressful for patient, and what is best for sample
always get supplies prepared before grabbing patient!!

Question 4

CBC blood tubes

Answer 4

small mammals: EDTA
birds: EDTA or Heparin
reptiles: Heparin
Teleost fish: Heparin
Elasmobranchs: Heparin, EDTA

Question 5

chemistry blood tubes

Answer 5

Heparin (plasma separator)

Question 6

which machine should we use for automated counts: Idexx or Abaxis?

Answer 6

Abaxis because it can run smaller samples

Question 7

avian/reptile/fish manual WBC

Answer 7

can’t use automated: nucleated RBCs
hemocytometer: uses specialized slide and coverslip, dilute blood with special stains

Question 8

special stains for hemocyotmeter

Answer 8

Eosinophil unopette (phloxine B), Natt Herricks, or Rees Ecker

Question 9

eosinophil unopette (phloxine B) stain

Answer 9

advantages: commercially available, easy to learn
disadvantages: indirect count, uses differential to complete count, cell clumping/rupture can skew results

Question 10

Natt Herricks stain

Answer 10

advantages: direct count, can use for RBC counts
disadvantages: dilution is manual, not readily commercially available

Question 11

Rees Ecker stain

Answer 11

advantages: solution has higher osmolality, better for saltwater animals, doesn’t lyse RBCs, more accurate counts
disadvantages: made to highlight platelets, takes skill to use

Question 12

small mammal hemotology

Answer 12

great variation of MCV
sickling seen in deer
ovalocytes seen in camelids, llamas, and alpacas
monocytes are predominant in elephants
hyposegmentation seen in chinchilla neutrophils
ferrets have higher PCV, blood clots fast

Question 13

mammalian heterophil

Answer 13

granules don’t stain
functionally equivalent to a neutrophil
hard to tell apart from eosinophils but eosinophils are brighter
seen in g. pigs, hamsters, gerbils

Question 14

Kurloff bodies

Answer 14

guinea pig lymphocytes
they are intracytoplasmic inclusions: smooth or granular
origin and function unknown: suspected to be a killer cell

Question 15

avian erythrocytes

Answer 15

oval, nucleated, have dense chromatin
erythroplastid: anucleated eyrthrocytes
polychromasia more common, smaller and rounder, larger nucleus with loose chromatin, basophilic cytoplasm

Question 16

what are all the different types of leukocytes in birds?

Answer 16

granulocytes: heterophil, eosinophil, basophil
agranulocytes: monocytes, lymphocytes

Question 17

avian heterophils

Answer 17

segmented nucleus
cytoplasm: round, pink granules
can see blue eosinophils in barred owls: granules stain pale indigo

Question 18

avian basophils

Answer 18

more common than in dogs and cats
smaller than other granulocytes
unsegmented nucleus
cytoplasm: basophilic, round granules, degranulates in Diff Quick

Question 19

avian lymphocytes/monocytes

Answer 19

look like mammal cells
can see reactivity
in some birds lymphocytes outnumber heterophils
lymphocytes can have irregular cytoplasm known as blebs, granules can be normal

Question 20

avian thrombocytes

Answer 20

not platelets
round to oval with round to oval nucleus
clear cytoplasm
often found in clusters

Question 21

why is reptile and fish blood harder to deal with?

Answer 21

fewer established reference ranges
more likely to see hemolysis which causes a pink background and lysed cells
blood is more delicate so use alternative blood smear techniques
PCV/TP can be different
immature RBCs more common

Question 22

reptile erythrocytes

Answer 22

erythrocytes are larger than avian

Question 23

reptile heterophils

Answer 23

nucleus bilobed in lizards, unsegmented in chelonians and snakes, rod-shaped granules

Question 24

reptile eosinophils

Answer 24

unsegmented nucleus, round granules

Question 25

reptile monocytes/azurophils

Answer 25

azurophils are smaller than monocytes
have pink “granules” in the cytoplasm
more basophilic cytoplasm
could be immature form
might list separately from monocytes or count them as the same

Question 26

amphibian hematology

Answer 26

samples are difficult to obtain due to lack of venipuncture sites
lack of normal reference data
results can vary on temperature, season, age, sex
lymphocyte contamination can occur

Question 27

hematopoiesis in cartilaginous fish

Answer 27

no bone marrow or lymph nodes
have Leydig organ where granulopoiesis occurs
Epigonal organ: tissue closest to mammalian bone marrow, where lymphopoiesis and granulopoiesis occurs
spleen/peripheral blood: erythropoiesis

Question 28

which stains are the best choices for WBC count of elasmobranchs?

Answer 28

Natt Herricks or Rees Ecker

Question 29

elasmobranch granulocytes

Answer 29

neutrophils, CEG (coarse eosinophilic granulocyte), FEG (fine eosinophilic granulocyte)

Question 30

elasmobranch agranulocytes

Answer 30

monocytes and lymphocytes

Question 31

elasmobranch erythrocytes

Answer 31

oval, nucleated

Question 32

elasmobranch thrombocytes

Answer 32

agranular (typical): oval to round small cell with scant blue cytoplasm
granular (GT): oval to round cells with tiny pink granules packing the edges

Question 33

CEGs

Answer 33

coarse eosinophilic granulocyte
round to segmented nucleus
pale to sky blue cytoplasm
larger round pale pink to eosinophilic granules

Question 34

FEGs

Answer 34

fine eosinophilic granulocytes
round to segmented nucleus
usually pale to colorless cytoplasm
granules are small, round to elongated

Question 35

teleost hematopoiesis

Answer 35

have bones but no medullary cavity
thymus: lymphopoiesis
spleen: lymphopoiesis
kidney: granulopoiesis, erythropoiesis (peripheral blood)