Jason M. Eberhardt DVM, MS, DACVIM
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S One of the most common CBC abnormalities
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10-30% of patients
Why is it still so confusing?
S Back to basics
S Systematic approach to anemia
S Avoiding common pitfalls

S “You need to have the correct diagnosis before you can recommend the correct treatment.”
S “If you always have the correct diagnosis then you’re not a really veterinarian…you’re probably a breeder.”
S “You need to run a minimum of 5 diagnostic tests prior to starting steroids…”

S Mean Corpuscular Volume (MCV) – Avg. RBC size
S Macrocytosis
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Microcytosis
Normocytic
S Mean corpuscular Hgb concentration (MCHC) – [ ] of Hgb vol. RBC
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Hypochromic
Normochromic
Macrochromic
S Reticulocytes – Immature RBCs released from B.M. early
S Normoblasts/metarubricytes – nucleated erythrocytes

S Poikilocytosis – Variation of RBC shape
S Rouleaux – Stacks of coins
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Small amount is normal
Increased fibrinogen or acute phase proteins
S Typically seen in inflammatory conditions
S Autoagglutination – Aggregate in grapelike clusters
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Must be differentiated from rouleaux
Rouleaux disperses when blood is mixed with saline

Rouleaux Autoagglutination

S Where do I start…….
S Back to basics!!!

S Remember the Total Protein!!!
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It’s the other half of “blood”
It’s cheap!
It’s fast
S DO NOT OVERLOOK!
S Are just the RBCs being affected or the plasma as well?

S Morphologic classification
S RBC indices
S Bone marrow response
S Regenerative vs. Non-regenerative
S Description of poikilocytosis?
S Macrocytic, hypochromic, regenerative anemia with marked spherocytosis

S Usage of RBC indices (MCV/MCHC) to “describe” the
RBCs.
S Remember MCV/MCHC are MEAN calculations
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Large # of RBCs affected prior to increases/decreases
Allows characterization of anemia into a category
Helps with ranking differential diagnoses
S Are found on nearly all in-house CBC units

S Most common
S “Normal” RBCs
S Most commonly denotes a non-regenerative anemia
S Usually lacks RBC morphology changes
S “Pre-regenerative”
S First 1-3 days of acute loss/lysis

S Usually indicates a regenerative anemia
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Reticulocytes are relatively larger then mature RBCs
Hypochromic because Hgb synthesis is not complete
S Only 8% of 6752 patients with reg. anemia had both increased MCV & decreased MCHC
DiNicola et al.

S Usually misclassification due to insensitivity of MCV/MCHC
S Autoagglutination?
S Feline Leukemia
S Poodles – Congenital dyserythropoiesis
S Not anemic
S Large problem in humans
S B12 &/or folate deficiency
S Role in veterinary medicine is questionable

S Consistent with an iron deficiency anemia
S Inadequate amount of Hgb is produced
S Typically seen in chronic conditions
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GI blood loss
Severe parasitism
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PSS & Hepatic atrophy
Myelodysplastic syndromes
S Congenital: Akitas, Shiba Inu, Chow breeds
S Not typically hypochromic

S Is there a regenerative response?
S Evaluation of reticulocytosis
S No reticulocytosis/polychromasia expected during first 1-3 days (maybe not at all if anemia stays mild)
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Response peaks 4-5 days (with normal B.M.)
Erythrocyte indices start to change 7-14 days

S Normal patient should have <45,000-60,000 absolute retic count
S Absolute counts
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60,000-150,000 Early/mild response
150,000-250,000 Mild-moderate
>250,000-500,000 Moderate-Marked
S Relative %
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1-4 % - Mild
5-20 % - Moderate
> 20 % - Marked

S Loss vs. Lysis
S LOOK AT TOTAL PROTEIN!!!!
S External blood loss
S Low to low-normal T.P.
S Hemolytic disease
S High to high-normal T.P.

S PCV does not fully reflect severity first 1-3 days
S Reticulocytosis should start by day 3
S Peak reticulocytes day 4-7
S PCV increases to low normal w/in 2 wks
S May take up to 4-5 weeks to return to normal
S Mild anemia does not stimulate strong erythropoietin release

S Iron deficiency and negative protein balance develops after
“several” weeks in adults
S Occurs more rapidly in young animals (low iron stores)
S Initially non/”pre” regenerative
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Period of regenerative anemia depending on severity
Eventually returns to being poorly/non-regenerative
Often have thrombocytosis
S Remember RBC indices do not change for 7-14 days
S Getting blood transfusions???

S Hemolysis is a mechanism NOT a “disease”
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Lots of “non” immune mediated causes
S Low serum phosphorus
Normal to increased T.P.
S Spherocytosis and/or autoagglutination
S Over interpretation is common
S Can be seen in diseases that are not “primary”
S Positive Coomb’s Test?

S Identifies presence antibodies/compliment on RBCs
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They may/may not actually be directed towards RBCs
This may/may not actually cause damage to RBCs
S Neither highly specific or sensitive for IMHA
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Positive in 60-70% of cases
Positive results – should have other evidence of IMHA
Effect of steroids?
S **NOTE** – What is the end point of the test?????

S Try to subclassify into intravascular vs. extravascular
S Alters differential diagnosis
S Intravascular – Rapid breakdown in vascular system
S Pink urine, pink serum
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Hemoglobinuria best indicator
Hyperbilirubinemia typically more profound then in extravascular
S Extravascular – removal of RBCs by spleen, liver, B.M.
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More common
Often has icterus, splenomegaly, hepatomegaly

S “Immune-mediated” is a mechanism NOT a disease.
S Can be 2 nd to a number of possible causes
S Infectious – Babesiosis, Ehrlichiosis, Leishmaniasis,
Rickettsioses, Mycoplasma haemofelis, FeLV
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Neoplasia
Drugs
S Can be initially non-regenerative (esp. in cats)

“Penny” 6 year FS Cocker
S Presented for severe lethargy, “yellow skin” and “peeing blood”
S Severe, macrocytic, normochromic strongly regenerative anemia with mild-moderate spherocytosis
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Slide agglutination negative
High total protein
S Abdominal ultrasound WNL
S Infectious disease titers all negative

S Needed multiple transfusion in a 5-6 day period
S Continued to have hemolysis despite aggressive immunosuppressive therapy
S Where do we go from here???
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“Peeing” blood – hemoglobinuria
Intravascular hemolysis

S Immune mediated
S Phosphofructokinase deficiency
S Eng. Springers, Amer. Cockers
S Babesia infection
S Snake envenomation
S Heavy metal to toxicity
S Zinc
S Copper

“Penny” 6 yr FS Cocker Spaniel
S Presented for severe lethargy, yellow skin and “peeing blood”
S Severe, macrocytic, normochromic strongly regenerative anemia with mild-moderate spherocytes
S Abdominal ultrasound WNL
S Infectious disease titers all negative

S Presented with clinical evidence of anemia
S Severe leukocytosis (54,000), severe anemia (9%), high normal platelets, mild-moderate reticulocytosis
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Total Protein – 4.9 g/dL
VF, Ehr. Neg.

S Started on prednisone, cyclosporine, doxycycline
S Needed 2 nd transfusion 1 week later
S Added azathioprine
S PCV still low 2 weeks later
S Chest rads and abd. u/s WNL
S Increased prednisone, continued on cyclosporine and azathioprine
S 3rd transfusion in 4 weeks
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Added leflunomide
Repeat abdominal ultrasound WNL

S Initial PCV/TP at EAC
S 12%/4.8
S Reference lab work
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Hypoalbuminemia (2.6 g/dL), globulin WNL (1.7 g/dL),
BUN increased (mild), Total bilirubin (mild)
Inflammatory leukogram
Severe reticulocytosis

S Horrible IMHA???
S Another type of hemolytic anemia?
S GI bleeding (from prednisone?, GI mass?)
S Diagnostic plan???????????
S Explain the decreased total protein

S Very common!!!
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Usually normocytic normochromic
S Microcytic, hypochromic anemias
Usually no poikilocytosis
S Huge majority are mild-moderate in severity
S 2 nd to systemic disease

S Is neutropenia and/or thrombocytopenia also present?
S What is the duration of clinical signs?
S How severe are the clinical signs?

S Mild-moderate NR anemia
S Search for an underlying disease first
S Anemia of chronic/inflammatory disease
S Neoplasia, renal disease, hepatic disease, infectious, inflammatory, endocrine
S Drugs

S Toxicity
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Estrogen?
Drugs
S Renal disease
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More than just decreased erythropoietin
Chronic dz, decr. RBC lifespan, ineffective production, blood loss

S Bone marrow exam
S Took a long time to develop
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Can take even longer to resolve
Can still be very confusing and frustrating

S Immune mediated
S Maturation arrest vs. Pure Red Cell Aplasia
S Myelophthisic syndromes - multiple cell lines often affected
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Aplastic anemia – B.M. replaced by fat
S Can be 2 nd to chronic ehrlichiosis
Myelofibrosis – B.M. replaced by fibrous
Myelonecrosis – Drugs, toxins, viral
Neoplasia

S Progressive lethargy, wt. loss for several weeks
S Marked (12%), macrocytic, normochromic anemia
S Total protein 6.2 g/dL
S Absolute reticulocyte count 40,000
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Retic. total 2%
Corrected 0.65%
S FelV/FIV negative
S Chest radiographs, abdominal ultrasound WNL

S 50% of cats with immune mediated disease initially had a non-regenerative response
Kohn et al. 2006
S 2/3 were <3 years (range was 1-9 yr)
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Bone marrow disease – 53%
Infectious – 22%
Hemolysis – 11%
Immune Mediated – 6%
S Severity of anemia associated with B.M. disease
Korman et al. 2013

S Owner noticed gradual decline
S More consistent with non-regenerative disease
S Transfusion
S Recheck 2-3 days later vs. bone marrow now
S Marked erythroid hypoplasia/aplasia
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Immune mediated vs. FelV
Bone marrow IFA positive for FelV
Stutzer et al. 2010

S Many have little/no clinical significance
S Anisocytosis, elliptocytes, codocytes, leptocytes, *echinocytes*
S Spherocytes – Evidence of hemolysis
S Acanthocytes - Hemangiosarcoma, hepatic dz
S Schistocytes - DIC, Fe def, CHF, myelofibrosis, hemangiosarcoma, other neoplasia

S Anemia is a common abnormality
S Cause can often be elusive
S Vital to approach systematically
S RBC indices, bone marrow response, poikilocytosis
S DON’T FORGET THE TOTAL PROTEIN!!!

QUESTIONS???