Exam I Material Flashcards
1
Q
If you have an abscess, would you expect to see neutrophilia or neutropenia?
A
Neutrophilia
1
Q
T/F: Blood loss causes thrombocytopenia
A
False
Gotcha, biatch!
2
Q
What is the most diagnostically useful finding in dogs with immune mediated hemolytic anemia (IMHA)?
A
Spherocytosis
2
Q
While Greyhounds generally make great blood donors, many of them carry blood-borne diseases. The most common blood-borne disease, that we see in ~85% of greyhounds, is:
A
Babesia canis
~85% of Greyhounds carry positive titers for Babesia canis
2
Q
What might be the cause of Heinz Body Anemia in a cat?
A
Anything that causes oxidative damage:
- Acetaminophen
- Propylene Glycol
- Onions, Garlic
- Lymphoma, hyperthyroidism, diabetes
Just to name a few
3
Q
Briefly describe the formation of a primary hemostatic plug:
A
Adherence, Activation, Secretion, Aggregation
Platelets adhere to subendothelium and undergo activation (including shape change), secrete their granules, and aggregate to form a platelet plug
4
Q
When are increased PIVKA values seen?
A
Proteins Induced by Vitamin K Antagonism (PIVKA) will be increased in:
- Vitamin K antagonism/deficiency
- Human hepatocellular carcinomas
4
Q
What are the two blood systems in the cat?
A
**AB system **and Mik system
5
Q
Briefly describe how neutrophils develop toxic change:
A
early release
Neutrophil “toxic change” is normally due to rapid multiplication and shortened maturation time in the bone marrow, resulting in persistence of ribosomes. This accelerated production rate is common in inflammation
6
Q
T/F: DIC may be caused by induction or exposure of tissue factor or other activators of coagulation
A
True
Disseminated Intravascular Coagulation (DIC) may be caused by induction or exposure of tissue factor or other activators of coagulation. This may be observed in cases of sepsis, tissue necrosis, neoplasia, etc.
7
Q
Which factor of the coagulation cascade is required for the initiation of secondary hemostasis?
A
Tissue factor (Factor III)
7
Q
What is the significance of decreased fibrinogen concentration?
A
Significance of decrease:
- Consumption due to hypercoagulation (excessive conversion of fibrinogen to fibrin)
- Decreased production by the liver
7
Q
What is the most prominent feature of a feline ‘excitement’ response?
A
Lymphocytosis
Increased blood flow through microcirculation results in shift of leukocytes from marginated pool to the circulating pool. This can result in a 2-fold increase in leukocyte concentration. Lymphocytosis is the most prominent feature of feline excitement response
8
Q
Name a few diseases that may cause a reactive thrombocytosis:
A
- Chronic Inflammatory Disease
- Iron deficiency anemia
- Chronic hemorrhage
- IMHA
8
Q
When crossmatching: If you do not observe agglutination, is that considered a positive or negative crossmatch?
A
Negative Crossmatch
If there is no agglutination or hemolysis, the recipient is not likely to have a transfusion reaction from the donor’s RBCs. Go ahead and transfuse!
10
Q
Which morphological abnormality is commonly seen in red blood cells 24-48 hours following rattlesnake envenomation?
A
Echinocytes
11
Q
What is the most common blood type in cats?
A
Type A
>95% of all cats have Type A blood
12
Q
When examining a blood smear to analyze platelet concentration, what is the minimum number of platelets you should expect per high power field (100x)?
A
7-10 platelets
Horses: minimum of 4-7
Increased numbers of enlarged platelets suggests active production of platelets
13
Q
Microcytic anemia in domestic animals is most often associated with:
A
Iron deficiency
14
Q
Stabilization of the platelet plug via fibrin meshwork is referred to as:
A
Secondary hemostasis
This usually only occurs in large defects (In small defects –> platelets only)
16
Q
What does Buccal Mucosal Bleeding Time evaluate?
A
Adequate platelet number and function
To perform the test, make a standardized incision, blot the blood gently, and measure time for bleeding to cease.
Normal time for dogs: 1-5 mins
Normal time for cats: 1-3.5 mins
17
Q
T/F: Yellow coloration of plasma may be considered normal in large animals
A
True
Yellow coloration of plasma may be indicative of icterus in both small animals and large animals.
However, in large animals, it may be due to carotenoid pigments in their diet (in this case, it would be considered normal)
17
Q
Dogs that are only DEA ____ and/or DEA ____ are often used as “universal donors”
A
Dogs that are only DEA 4 [+] and/or DEA 6 [+] are often used as “universal donors”
DEA 4 and 6 are expressed in 98% of dogs. Most dogs carry the antigen and do not develop antibodies.
17
Q
T/F: Cats with Type B blood have strong natural isoantibodies against Type A, which can lead to severe and lethal transfusion reactions
A
True
18
Which laboratory tests could you use to test platelet concentration and morphology (size)?
**Blood smear** and **hematology analyzers**
When testing platelet concentration in blood, collect blood in EDTA tubes (purple/lavender top). The EDTA present in the tube binds calcium ions, stopping the coagulation cascade
18
Which feline blood type is associated with strong isoantibodies?
**Type B**
Cats with **Type B** blood have strong natural isoantibodies against **Type A**, which can lead to severe and lethal transfusion reactions
18
Heinz bodies are inclusions within red blood cells composed of:
**oxidatively denatured hemoglobin**
Cats are most susceptible to Heinz body formation. It occurs with diseases such as lymphoma, hyperthyroidism, and diabetes mellitus
20
If an animal has immune-mediated hemolytic anemia **and** immune-mediated thrombocytopenia, what is the name of this syndrome?
**Evan's Syndrome**
21
What does a PCV value tell you?
**Relative quantity of RBCs to whole blood**
(what % of whole blood is made up of red blood cells)
22
Keratocytes are unique to *which disorder*?
**Iron deficiency anemia**
23
Which factor drives amplification of secondary hemostasis? Which 4 factors does it affect?
**Thrombin **is the key factor that promotes amplification of 2° hemostasis.
## Footnote
*It affects factors Va, VIIIa, VII, and XI*
24
The presence of macroplatelets is suggestive of:
**increased platelet production**
24
If you are given a blood panel and notice a low platelet count, but all other coagulation tests are normal, what should you be thinking with regard to this patient?
**Immune-mediated thrombocytopenia [ITP]**
This patient's body is attacking its own platelets!!!
25
Polychromasia is indicative of:
**blood loss or blood destruction with subsequent regenerative response**
Polychromatophilic cells are young erythrocytes that have been released early
25
T/F: Most cats are *Mik* negative
**False**
_Most cats are *Mik *positive_. Cats *without* the *Mik* antigen have *Mik* alloantibodies.
26
What are the two major mechanisms of **thrombocytosis?**
* Increased production
* Increased distribution in plasma
## Footnote
*Animals are usually asymptomatic with regard to the increased platelet count*
26
What are the most immunogenic blood types in dogs?
**DEA 1.1 **and **DEA 1.2**
DEA 1.1: ~45% of population
DEA 1.2: ~20% of population
26
The presence of **spherocytes** is suggestive of:
**Immune-Mediated Hemolytic Anemia [IMHA]**
Spherocytes are erythrocytes that appear small and lack central pallor
28
What is the major regulatory enzyme for thrombopoiesis?
**Thrombopoietin**
Thrombopoietin is produced in the liver and the kidney. It stimulates the production and differentiation of megakaryocytes.
29
T/F: Hemorrhage alone is usually the cause of significant thrombocytopenia
**False**
Hemorrhage alone *does not* usually cause significant thrombocytopenia.
Exception: _acute severe hemorrhage may result in mild thrombocytopenia_
29
Which laboratory test is most likely to be helpful in determining whether a regenerative anemia is due to extravascular hemolysis or blood loss that occured the day before?
**Plasma Protein Concentration (TP)**
If the anemia is due to extravascular hemolysis, then the TP should be normal. However, if the anemia is due to blood loss, the TP should be decreased
31
What would be the most likely cause of lymphocytosis in a dog in St. Kitts?
**Ehrlichiosis**
31
In which animal is **Rouleaux formation** of RBCs considered normal? What does the formation suggest in other animals?
Rouleaux formation is normal in **horses**.
It suggests *increased globulin* in small animals
32
1/3 of platelets are found in the \_\_\_\_\_\_\_\_\_
**spleen**
32
T/F: Increased FDPs inhibit platelet function and fibrin polymerization
**True**
Increased Fibrin Degradation Product (FDPs) inhibit platelet function and fibrin polymerization ONLY when FDPs are *pathologically increased* (e.g. DIC). It is not a 'normal' control mechanism
33
What is the significance of **increased fibrinogen concentration**?
An increased fibrinogen concentration can be indicative of **inflammation.** You may also see a relative increase with **dehydration**.
34
In a **major crossmatch,** what is tested from the recipient?
What is tested from the donor?
In a major crossmatch, the **patient's serum** and the **donor's RBCs** are tested
36
Increased FDP and D-dimers are commonly associated with:
**Disseminated Intravascular Coagulation (DIC)**
If you see a lot of Fibrin Degredation Products (FDP) and D-dimers, you know there is a high amount of fibrinolysis taking place. The usual indication is DIC.
37
What are the 2 major blood systems in dogs?
**DEA **and **Dal**
DEA = Dog Erythrocyte Antigen
Dal = a common antigen in most dogs, but is lacking in some dalmations
38
If a patient's platelet count is lower than the *lower reference interval (LRI)*, the patient has:
**thrombocyto**_penia_****
The degree of thrombocytopenia is gauged based on how much lower the platelet count is than the reference interval.
***If the patient has \<20,000/µL, that patient could spontaneously hemorrhage!***
40
T/F: Splenectomy is almost always required in the pathogenesis of hemolytic anemia associated with *Mycoplasma haemocanis*
**True**
**Splenectomy** predisposes animals to acute infection by *Mycoplasma haemocanis*
41
If you see an increased PT in a patient, what is the significance of that finding?
**Factor VII deficiency** or **deficiency/inhibition of common pathway factor**
## Footnote
*\*\*Prothrombin time (PT) is a good screening test for Vitamin K deficiency because of the short t1/2 of Factor VII\*\**
41
T/F: Severe immune-mediated thrombocytopenia (2,000/µL) will result in a prolonged ACT.
**True**
Any severe thrombocytopenia less than 10,000/µL can cause slight prolongation of ACT (Activated Clotting Time)
43
What is the difference between -penia and -philia?
- penia = fewer (e.g. neutropenia)
- philia = more (e.g. neutrophilia)
44
T/F: DIC is caused by continuous activation of coagulation and fibrinogenesis
**False**
DIC is caused by continuous activation of coagulation and fibrino**_lysis_**
The result is thrombosis of the microvasculature and depletion of coagulation factors and platelets (ultimately a lot of bleeding)
45
aPTT requires ~\_\_\_% deficiency of factor before prolongation is detected
aPTT requires **_~70%_** deficiency of factor before prolongation is detected
\*\*This is a more sensitive test than ACT\*\*
47
Which test(s) would you use in the *clinical setting* to evaluate platelet function?
**Bleeding time tests**
Buccal mucosal bleeding time; cuticle (toenail) bleeding time
48
T/F: It is common to see an increased MCHC in a cat with an elevated reticulocyte count following acute blood loss
**False**
During a regenerative response following acute blood loss, Mean Corpuscular Hemoglobin Concentration [MCHC] is expected to be *decreased*
*\*\*The decreased MCHC is due to the presence of many reticulocytes that are still making hemoglobin\*\**
50
Which laboratory test(s) would be useful in analyzing **platelet production**?
**Bone marrow aspirate**
Bone marrow aspirates (BMA) evaluate megakaryocyte number and morphology
52
T/F: Von Willebrand Factor is a blood glycoprotein that is important in red blood cell adhesion
**False**
Von Willebrand Factor is a blood glycoprotein that is important in _**platelet adhesion**._
vWF binds to GP1b on the platelet and serves as a bridge between platelets and collagen.
53
A stress leukogram is characterized by:
**lymphopenia, neutrophilia (not greater than 2x reference interval), eosinopenia**
A stress response occurs with illness, pain, metabolic disturbances, tx with corticosteroids, corticosteroid-producing tumors
\*\**do not confuse the neutrophilia of stress with inflammation*\*\*
54
What is a "left shift" and what is it indicative of?
**↑ conc. of immature neutrophils; inflammation**
A left shift is an increased concentration of immature neutrophils in the blood (usually band neutrophils, but may include metamyelocytes). Left shifts can occur with neutrophilia, normal concentration of neutrophils, or neutropenia.
*\*\*If a left shift occurs with neutropenia, it is a more severe inflammatory response\*\**
55
Where is urea sythesized and what is the precursor molecule?
**Liver, ammonia**
55
**Basophilic stippling** is considered normal in *which species*?
**ruminants**
Basophilic stippling is an abnormal aggregation of ribosomes that appear as small basophilic granules. You may see it associated with very regenerative anemia in cats and dogs.
\*\**If you see significant basophilic stippling in small animals, consider Lead Poisoning*\*\*
56
Which stain(s) is/are used to view **Heinz bodies**?
**NMB** or **Brilliant Cresyl Blue**
When stained with vital stains such as new methylene blue (NMB) or brilliant cresyl blue, Heinz bodies appear as blue structures.
57
If you see *increased albumin* in a patient, what should you be thinking immediately?
**Dehydration**
57
**Spontaneous hemorrhage** occurs when platelet count is:
***Less than 20,000/µL***
58
T/F: Dogs, cats, horses, and cows all release reticulocytes
**False**
Horses do *not* release reticulocytes
58
What platelet count would you expect to observe in a case of **warfarin toxicosis**?
Platelet count is usually normal
## Footnote
*However, PT, aPTT, & ACT will be prolonged, and PIVKA will be positive*
59
Which blood tube should be used when testing platelet concentration in blood?
**EDTA (Purple/Lavender Top)**
The EDTA present in the tube binds calcium ions, stopping the coagulation cascade.
60
If your patient presents with anemia, low serum iron, and microcytosis, what should you be thinking?
**Iron Deficiency Anemia**
61
What result would you expect to see for **intrinsic tests** in a case of **warfarin toxicosis**?
**aPTT** and **ACT** will be prolonged
63
ACT requires ~\_\_\_% deficiency of factor before prolongation is detected
ACT requires **_~95%_** deficiency of factor before prolongation is detected
64
**Disseminated Intravascular Coagulation (DIC)** generates fibrin strands that sever RBCs as they try to pass through a thrombus, leading to the formation of *what type of cell*?
**schistocytes**
66
What is the 1 coagulation test that accesses the extrinsic/common pathway?
**Prothrombin Time (PT)**
PT measures time for fibrin clot formation in* citrated plasma + tissue factor + Ca2+ + platelet phospholipid substitute*
PT requires ~70% deficiency of factor before prolongation is detected
67
How does the coagulation panel appear in the **consumptive phase** of DIC?
↑aPTT, ↑PT, ↑ bleeding time, ↑FDP, ↑ D-dimers
↓fibrinogen, ↓PLT, ↓AT
69
Which portion of a blood smear would you read to look for parasitic organisms?
**Feathered edge**
71
What are the two major end-products of fibrinolysis?
**Fibrin Degradation Products [FDPs] **and **D-dimers**
72
Give 2 examples of when you may see falsely decreased platelet concentrations on a blood analyzer:
**macrothrombocytes** and **clumping**
Pseudothrombocytopenia may occur if the platelets are too big (macrothrombocytes) or if they are clumped
73
T/F: Bleeding tests are useful for testing fibrin plug formation
**False**
Bleeding tests test the ability of platelets to form a ***platelet plug***. They do not test fibrin plug formation
74
T/F: Naturally occuring alloantibodies are not present in canines
**False**
Natural alloantibodies *can* occur. If a dog is exposed to certain blood types, they may already have alloantibodies
75
Which feline blood type is considered a "universal donor"?
**TRICK QUESTION**
**_Cats do not have "universal donors"_**
All cats have naturally occurring alloantibodies. *Blood type all cats prior to transfusion!*
However, there are cats with Type AB blood (very rare) that are "*universal recipients"*
76
T/F: Dogs can have more than 1 blood type
**True**
*For instance, dogs can be DEA 1.1, 4, 6 positive, etc.*
78
T/F: **von Willebrand Disease (vWD)** is a platelet defect that results in decreased adhesion
**False**
von Willebrand Disease (vWD) is a defect in the ***adhesion molecule that binds platelets during initiation of a platelet plug, ***resulting in decreased platelet adhesion. _It is not a defect in the platelets themselves_. vWD is an inherited disorder.
79
Where is blood most commonly lost in the case of **chronic blood loss**?
**Intestine**
Blood loss via the intestine is most common with regard to chronic blood loss
*(e.g. GI ulcer, bleeding GI tumor, blood consuming parasites)*
80
Which blood tube would you use when collecting a sample for coagulation tests?
**Sodium Citrate Tube (Blue Top)**
81
Many drugs and chemicals that cause Heinz body formation also cause a condition characterized by decreased O2-carrying capacity, known as:
**methemoglobinemia**
With methemoglobinemia, iron is in a ferric state, incapable of carrying oxygen
83
Name the two phases of DIC.
In which of these phases do we observe massive bleeding?
**Hypercoagulable phase (1st)** and **Consumptive phase (2nd)**
***Massive bleeding occurs in the consumptive phase*** as a result of consumption of platelets, coagulation factors, and antithrombin
84
T/F: Döhle Bodies are an inherited neutrophil abnormality
**False**
Döhle Bodies are denatured aggregates of free ribosomes associated with _toxic neutrophils._ Döhle bodies are an ***acquired** *neutrophil abnormality, not an inherited one
85
How would you **_macro_**scopically interpret a crossmatch? What about **_micro_**scopically?
Macroscopically, you would check for **hemolysis** and check for **agglutination.**
Microscopically, you would check for **agglutination** under the microscope.
*If there is agglutination, then the crossmatch is positive. If there is no agglutination, the crossmatch is negative.*
86
What are the two coagulation tests that access the intrinsic/common pathway?
**aPTT **and** ACT**
Activated Partial Thromboplastin Time (aPTT) measures time for fibrin clot formation in *citrated plasma*
Activated Clotting Time (ACT) measures time for fibrin clot formation in *non-anticoagulated whole blood*
**_aPTT is a more sensitive test than ACT!_**
87
T/F: Ethylene glycol toxicosis is often associated with Heinz body anemia in a cat
**False**
***Propylene* glycol toxicosis** is associated with Heinz body anemia in a cat.
89
T/F: Cats can have transfusion reactions following the first transfusion
**True**
90
An increased concentration of Howell-Jolly bodies is associated with:
**regenerative anemia, splenectomy, and suppressed splenic function**
Howell-Jolly bodies are nuclear remnants in erythrocytes
91
What are the two most antigenic blood types in the horse?
**Aa and Qa**
Aa and Qa are highly immunogenic and are implicated in neonatal isoerythrolysis.
There are no "universal donors" in equines
92
Which coagulation factors are dependent upon Vitamin K for their activity?
**II, VII, IX, X**
...that's two, seven, nine, and ten if you're not a roman numeral fan
93
Which cofactor is required for antithrombin to inactivate thrombin?
**Heparin**
Heparin allows antithrombin to bind thrombin in a 1:1 ratio to inactivated thrombin
94
T/F: Howell-Jolly bodies are formed as a result of oxidatively denatured hemoglobin
**False**
***Heinz Bodies*** are oxidatively denatured hemoglobin
95
Thrombocytopenia can be the result of abnormal distribution of platelets; more specifically the sequestration of platelets in large vascular beds.
## Footnote
**Which 3 conditions are most associated with this presentation?**
**splenomegaly, splenic torsion, neoplasia**
96
**Iron deficiency anemia** in adult animals is *almost always *due to:
**chronic blood loss**
(*in nursing animals, it's almost always due to inadequate intake of iron*)
98
Lack of a steroid response in a sick animal should trigger you to consider:
**hypoadrenocorticism**
99
Name a few *situations* that may cause a reactive thrombocytosis:
* Rebound from thrombocytopenia
* Post-splenectomy
* Response to some drugs (Vincristine)
* Excitement & exercise (epinephrine --\> splenic contraction)
100
T/F: Increased Mean Platelet Volume (MPV) is suggestive of increased thrombopoiesis
**True**
101
What are the major mechanisms for thrombocytopenia?
****_P_**roduction, **_C_**onsumption, **_D_**estruction, **_S_**equestration, **_L_**oss**
How I remember it:
***_P_**latelet **_C**_ount _**D**_own _**S**_uper _**L_**ow*
102
Which species is most susceptible to **copper toxicosis**?
**Sheep**
Copper tends to be stored in the liver. Stressful events lead to the release of stored Cu, which can result in *hemolytic anemia, hemoglobinemia, hemoglobinuria, and Heinz body formation*
103
A neutrophil concentration *greater than 2x the upper limit* of the reference interval indicates:
**inflammation**
104
Which blood type is not always expressed in **Dalmatians**?
***Dal***
*Dal* is ubiquitous in non-Dalmatians, but some dalmatians lack the *Dal* antigen. ***Dalmatians are at risk for acute and delayed onset of hemolytic transfusion reactions.***
106
An increase in the number or proportion of lymphocytes in the blood is termed:
**Lymphocytosis**
Magnitude and morphology is important for diagnosis. For instance, if you have a lymphocyte count that is way way over the reference interval, it's likely that you're dealing with *lymphocytic leukemia*
107
When crossmatching: If you observe agglutination, is that considered a positive or negative crossmatch?
**Positive Crossmatch**
If agglutination or hemolysis are detected, the recipient **is at risk** for a transfusion reaction. **Do not transfuse** from this donor!!
108
List some of the clinical features associated with **thrombocytopenia**
* mucosal bleeding
* petechiation
* ecchymosis
* spontaneous hemorrhage: PLT count
* +/- hemorrhagic anemia
109
T/F: Chediak-Higashi syndrome is an inherited neutrophil abnormality
**True**
110
What RBC morphological abnormalities are associated with canine hemangiosarcoma?
**Schistocytes **and** acanthocytes**
111
Briefly describe the mechanism of **warfarin toxicosis**:
**Warfarin toxicosis **essentially blocks the synthesis of Vitamin K (an essential compound for normal blood clotting). *The result is spontaneous and uncontrolled bleeding*.
112
Why might you get a coagulopathy in a patient with liver disease?
* **Decreased Synthesis** of coagulation factors
* Production of **dysfunctional factors** (failure to metabolize/reduce Vitamin K)
113
What are lymphoblasts in peripheral blood indicative of?
**lymphocytic leukemia**
lymphoblasts are not normal to see in peripheral blood
115
Which type of tube should be used for collection of a blood sample for a complete blood count?
**EDTA (Purple/Lavender Top)**
EDTA preserves cell morphology
116
In which species is neonatal isoerythrolysis most common?
**Horses**
(*felines are the next most common - "fading kitten syndrome"*)
117
T/F: Punctate and aggregate reticulocytes are both included in the reticulocyte count in cats
**False**
Aggregate reticulocytes become punctate reticulocytes. *_Punctate forms are not polychromatophilic with Wrights stain, and are not counted in the reticulocyte count._*
118
T/F: Blood first appears brown when 90% of hemoglobin is changed into methemoglobin
**False**
*Blood first appears chocolate brown at 30% methemoglobin.*
90% is significant because levels that high result in death!
119
T/F: Anemia of Inflammatory Disease is characterized by increased iron storage
**True**
With inflammatory disease, the body is trying to lower serum iron levels so the iron isn't available to organisms for their own reproduction
\*\**You would see lower serum _and_ storage iron in a case of chronic blood loss anemia*\*\*
120
Where in the body is **hepcidin **produced? What is it produced in response to?
**Liver; bacteria**
*Hepcidin is produced in the liver in response to LPS in Gram [-] bacterial cell walls.*
Hepcidin inhibits iron from leaving cells by removing and destroying ferroportin (the exclusive transporter of iron out of cells)
121
**Hepcidin** is a hepatic peptide that inhibits iron from leaving cells by removing and destroying \_\_\_\_\_\_\_\_\_\_\_\_
**Ferroportin**
Ferroportin is the *_only_* transporter that allows iron out of cells.
122
T/F: A myeloid:erythroid precursor (M:E) ratio of 1:1 to 3:1 in bone marrow can be normal
**True**
123
What is the end goal of **primary hemostasis**?
**Platelet plug**
124
What is the end goal of **secondary hemostasis**?
**Fibrin clot**
125
Which test will be prolonged if your patient is lacking von Willebrand factor (vWF)?
**Mucosal Bleeding Time**
126
What is the best way to tell if a horse has a regenerative anemia?
**Increased MCV**
127
Which factor of the coagulation cascade has the shortest half-life?
**Factor VII**
128
Name the three components that contribute to coagulation efficiency:
Factor V, Ca2+, and PLT membrane
