1What causes physiologic leukocytosis?
Epinephrine released during excitement or exercise.
2What happens to neutrophils during epinephrine-mediated physiologic leukocytosis?
They shift from the marginal pool to the circulating pool.
3What neutrophil pattern occurs with physiologic leukocytosis? Which animals commonly show physiologic leukocytosis?
1.Neutrophilia, often up to about 2× normal, without a left shift.
2. Excited, healthy young animals, especially cats and pigs.
4What lymphocyte change can occur with physiologic leukocytosis?
Lymphocytosis, especially in cats because 3:1 marginal pool (bigger) to circlating pool
5How long do epinephrine-mediated leukogram changes usually last?
Seconds to about 20–30 minutes.
6An excited young cat has neutrophilia and lymphocytosis without a left shift. What is the likely cause?
Physiologic leukocytosis from epinephrine.
7How can exercise affect the equine hemogram?
It can increase PCV (spleen squeezes blood), WBCs, neutrophils, and lymphocytes.
8What causes the corticosteroid-induced stress leukogram?
Endogenous or exogenous corticosteroids.
9How do corticosteroids cause neutrophilia? 3 ways EXAM
↑Release from marrow storage, marginal-to-circulating shift, and prolonged circulating time.
10Does corticosteroid-induced neutrophilia usually have a left shift? EXAM
No, unless the marrow storage pool is depleted.
11What four leukocyte changes characterize the classic canine stress leukogram? EXAM
Neutrophilia, lymphopenia, eosinopenia, and monocytosis.
12In which species is stress-associated monocytosis characteristic?
Dogs.
13Can corticosteroid neutrophilia occur at the same time as inflammatory neutrophilia?
Yes, inflammation causes left shift
14What is neutropenia?
A decreased blood neutrophil concentration.
15At what neutrophil count is a patient considered at increased risk for sepsis?
<500 neutrophils/µL.
16What are the two most common mechanisms of neutropenia?
Decreased neutrophil production and increased tissue demand.
17Which viruses can decrease neutrophil production?
Canine parvovirus, feline panleukopenia virus, and bovine viral diarrhea virus.
18Which retroviruses can decrease neutrophil production?
FeLV, FIV, and BIV.
19What toxins or drugs can decrease neutrophil production?
Bracken fern, estrogen, phenylbutazone, and phenobarbital.
20What infectious agents besides viruses can decrease neutrophil production?
Ehrlichia and Anaplasma.
21What medical treatments can decrease neutrophil production?
Radiation therapy and cancer chemotherapy.
22Which breed is classically associated with cyclic neutropenia?
Grey Collies.
23What 3 less common mechanisms can cause neutropenia?
Immune-mediated destruction, ineffective granulopoiesis, and sequestration in the marginal pool.
24What can cause sudden neutrophil sequestration into the marginal pool?
The initial response to endotoxin.
25What is leukergy?
Abnormal aggregation or “stickiness” of leukocytes, as can occur with endotoxemia.

26What is toxic change in neutrophils?
Morphologic abnormalities caused by accelerated granulopoiesis during strong inflammation.
27What causes toxic neutrophil changes?
Increased inflammatory cytokines/mediators, sometimes combined with bacterial toxins.
28What does marked toxic change most strongly suggest?
Severe bacterial infection, sepsis, or endotoxemia.
29Why should a fresh blood smear be used to evaluate toxic change?
EDTA causes time-dependent artifacts that can mimic toxic changes.
30What are the major features of neutrophil toxic change? EXAM
Döhle bodies, cytoplasmic basophilia, vacuolation, large size, and sometimes toxic granulation.
31What are Döhle bodies? EXAM
Blue cytoplasmic inclusions seen in toxic neutrophils.

32What does diffuse cytoplasmic basophilia look like in a toxic neutrophil?
The cytoplasm becomes abnormally blue.

33What does cytoplasmic vacuolation indicate in a toxic neutrophil?
Foamy-appearing cytoplasm associated with toxic change.

34In which species are abnormally large toxic neutrophils especially noted?
Cats.
35What is toxic granulation?
Persistent azurophilic/purple cytoplasmic granules in toxic neutrophils.

36What defines 1+ toxic change?
Döhle bodies only.
37What defines 2+ toxic change?
Döhle bodies plus cytoplasmic basophilia OR vacuolation.
38What defines 3+ toxic change?
Döhle bodies plus basophilia AND vacuolation, with or without toxic granulation.

39What defines 4+ toxic change?
Neutrophils are so toxic they may be difficult to distinguish from monocytes.

40What degree of toxic change generally suggests infection, sepsis, or endotoxemia?
2+, 3+, or 4+.
41Can mild toxic change occur without infection?
Yes; 1+ and occasionally 2+ can occur with strong noninfectious marrow stimulation like immune mediated hemolysis and tissue necrosis.
42What 3 cellular changes underlie toxic neutrophil morphology?
Increased ribosomes/ER (blue), lysosomal enzymes, and/or bacterial damage to cytoplasmic proteins and organelles.
43What does finding bacteria inside circulating neutrophils suggest?
- Septicemia with overwhelming infection and a poor prognosis.
uncommon
44What intracellular organism can form morulae in neutrophils of horses and dogs?
Anaplasma phagocytophilum.

45What are morulae?
Clusters of intracellular Anaplasma/Ehrlichia organisms visible within leukocytes.

46What protozoal organism can be identified within neutrophils?
Hepatozoon americanum.

47A horse with Strangles has purple granules remaining in its neutrophils. What morphologic change is present?
Toxic granulation associated with inflammation from Streptococcus equi.
