Exotic Hematology Flashcards
challenges of obtaining exotic blood
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
stains for exotic blood
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
sample handling
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!!
CBC blood tubes
small mammals: EDTA
birds: EDTA or Heparin
reptiles: Heparin
Teleost fish: Heparin
Elasmobranchs: Heparin, EDTA
chemistry blood tubes
Heparin (plasma separator)
which machine should we use for automated counts: Idexx or Abaxis?
Abaxis because it can run smaller samples
avian/reptile/fish manual WBC
can’t use automated: nucleated RBCs
hemocytometer: uses specialized slide and coverslip, dilute blood with special stains
special stains for hemocyotmeter
Eosinophil unopette (phloxine B), Natt Herricks, or Rees Ecker
eosinophil unopette (phloxine B) stain
advantages: commercially available, easy to learn
disadvantages: indirect count, uses differential to complete count, cell clumping/rupture can skew results
Natt Herricks stain
advantages: direct count, can use for RBC counts
disadvantages: dilution is manual, not readily commercially available
Rees Ecker stain
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
small mammal hemotology
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
mammalian heterophil
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
Kurloff bodies
guinea pig lymphocytes
they are intracytoplasmic inclusions: smooth or granular
origin and function unknown: suspected to be a killer cell
avian erythrocytes
oval, nucleated, have dense chromatin
erythroplastid: anucleated eyrthrocytes
polychromasia more common, smaller and rounder, larger nucleus with loose chromatin, basophilic cytoplasm
what are all the different types of leukocytes in birds?
granulocytes: heterophil, eosinophil, basophil
agranulocytes: monocytes, lymphocytes
avian heterophils
segmented nucleus
cytoplasm: round, pink granules
can see blue eosinophils in barred owls: granules stain pale indigo
avian basophils
more common than in dogs and cats
smaller than other granulocytes
unsegmented nucleus
cytoplasm: basophilic, round granules, degranulates in Diff Quick
avian lymphocytes/monocytes
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
avian thrombocytes
not platelets
round to oval with round to oval nucleus
clear cytoplasm
often found in clusters
why is reptile and fish blood harder to deal with?
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
reptile erythrocytes
erythrocytes are larger than avian
reptile heterophils
nucleus bilobed in lizards, unsegmented in chelonians and snakes, rod-shaped granules
reptile eosinophils
unsegmented nucleus, round granules
reptile monocytes/azurophils
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
amphibian hematology
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
hematopoiesis in cartilaginous fish
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
which stains are the best choices for WBC count of elasmobranchs?
Natt Herricks or Rees Ecker
elasmobranch granulocytes
neutrophils, CEG (coarse eosinophilic granulocyte), FEG (fine eosinophilic granulocyte)
elasmobranch agranulocytes
monocytes and lymphocytes
elasmobranch erythrocytes
oval, nucleated
elasmobranch thrombocytes
agranular (typical): oval to round small cell with scant blue cytoplasm
granular (GT): oval to round cells with tiny pink granules packing the edges
CEGs
coarse eosinophilic granulocyte
round to segmented nucleus
pale to sky blue cytoplasm
larger round pale pink to eosinophilic granules
FEGs
fine eosinophilic granulocytes
round to segmented nucleus
usually pale to colorless cytoplasm
granules are small, round to elongated
teleost hematopoiesis
have bones but no medullary cavity
thymus: lymphopoiesis
spleen: lymphopoiesis
kidney: granulopoiesis, erythropoiesis (peripheral blood)
