Leukocyte evaluation Flashcards
Normal leukocyte count for cats and dogs
5,000-15,000
Leukemoid response
Increase in leukocytes (about 50,000 leuks per micL)
Indicates serious acute inflammation
Looks like leukemia
Causes
1. Infectious processes: pyothorax, pyelonephritis, septic peritonitis, pyometra, abscesses, pneumonia
2. Immune-mediated disorders (IMHA), glomerulonephritis, polyarthritis, vasculitis
3. Differentiate from CML
4. Will mostly see in dogs because they ahve such a huge neut reserve in BM
Falsly elevated leukocyte count
Blood machines will count nucleated RBCs as leukocytes
Cats / Dogs / Horses normal leukocyte count
Neuts: 70%
Lymphocytes: 30%
Monocytes: 5%
Cattle / Ruminant normal leukocyte count
Neuts: 50%
Lymphocytes: 50 %
Normal neutrophil storage pool
Bone Marrow
Dogs > Cats > Horses > Cows and sheep
When evaulating leukocytes
Consider total amounts of cell lines, percentages can be misleading
Hypersegmentation in neutrophils
Five or more distinct nuclear lobes
Endogenous or exogenous glucocorticoids (older neutrophils staying in circulation because macs aren’t eating them after their 10 hrs in circulation)
Granulocytes
Basophils
Eosinophils
Neutrophils
Chediak-Higashi
Neutrophil function problem, cannot form phagolysosome
Neutrophilic granules seen in
Siamese cats and healthy foals
Left Shifting
More immature forms of neutrophils are coming out of bone marrow.
Sign of inflammation
Normal: 0-300 bands per mic/L
=> elevating bands = INFLAMMATORY LEUKOGRAM!!!
Neutrophilic toxicity
Refers to immaturity in neutrophils (from accelerated release from bone marrow) and indicates inflammation
=> Haven’t had time to clean up basophilic RNA in cytoplasm
Neutrophil tox rating
1+ toxicity = Dohle bodies OR basophilic cytoplasm
2+ toxicity = Dohle bodies AND basophilic cytoplasm
3+ toxicity = vacuolization of cytoplasm (foamy), Dohle bodies and basophilic cytoplasm
=> vacuolization is automatically 3+
4+ toxicity = granulation band ‘band neutrophil’
=> Band neut = immature neut
=> Segmented neut = mature neut
Tick borne disease
shifting leg lameness
thrombocytopenia
Regenerative left shift
Mature neutrophophils dominate.
Mature (segmented or ‘segs’) > immature (bands, metamyelocytes, myelocytes)
Better prognosis
Degenerative Left shift
Immature neutrophils dominate
Immature (bands, metamyelocytes, myelocytes) > segs
Worse prognosis, bone marrow is not keeping up with demand
Pelger-Huet Anomaly
Common in Australian Shepherd dogs
Cannot segment neutrophils, eosinophils, basophils but they are still functional
hypersegmented neutrophils normal in
Horses
Causes of neutrophilia
Epinephrine
=> causes BV and spleen to contract and release neuts
=> Physiologic neutrophilia
=> No neutrophil toxicity or left shift
Glucocorticoids
=> prednisone causes neutrophils not to egress from blood (lots of old neuts in blood)
Inflammatory leukogram
> 300 bands
More immature neuts (bands) usually with neut toxicity
Often occurs with underlying stress leukogram in hospitalized patients
Pysiologic leukogram
caused by stress/excitement
caused by vasoconstriction and splenic contraction
mature neutrophilia with lymphocytosis
30 minute blood draw
up to 20,000 lymphotyctes/micL in scared cats
Think physiologic or excitement with lymphocytosis in cats
Stress leukogram
Mature neutrophilia, lymphopenia, eosinopenia, monocytosis
LYMPHOPENIA may be only salient feature because of an underlying inflammatory leukogram
Glucocorticoid effects: neutrophils can’t exxtravasate out of circulation into tissues so they build up in blood (neutrophilia)
Mixed leukogram
Bands high > equal to 300/micL
Lymphopenia
Inflammatory leukogram with underlying stress leukogram (b/c of lymphopenia)
Neutropenia causes
- Increased utilization or destruction
- Acute infection before granulocytic hyperplasia has had time to occur.
- Overwhelming sepsis or endotoxemia!!
4. Look for an infection (migration into tissues is most common)
- Decreased marrow production
6. Estrogen toxicity in dogs and ferrets
- Viral infections (Parvo)
- Severe chronic ehrlichiosis
Common causes of eosinophelia
Cancers (Eosinophilic leukemia…very rare)
mast cell tumors
T-cell lymphomas
Dogs: round granules in eosinophils
Cats: rod shaped granules in eosinophils
Low protein in baby animals
could indicate failure of passive transfer
huge risk for infections
lack of maternal antibodies to protect them from pathogens and underdeveloped immune systems
Leukemia
Cancer from bone marrow
Lympoid leukemia
Myeloid leukemia
Acute: lots of blasts and immature forms in circulation
Chronic: cells are well-differentiated
Severity of leukemia (least to most)
Chronic Lymphocytic Leukemia < Chronic Myelogenous Leukemia < Acute Lymphocytic Leukemia < Acute Myelogenous Leukemia
Moderate to severe lymphocytosis in DOGS
Raises suspicion for chronic lymphocytic leukemia (CLL)
Do bone marrow or advanced DX
