Anemia Flashcards
1
Q
What does PCV depend on in the horse?
A
Age, breed, and level of fitness
2
Q
What percentage of the red cell mass can be stored in the spleen?
A
30%
Splenocontraction an increase PCV by up to 50%
3
Q
What is the PCV in the spleen?
A
~80%
4
Q
What kind of horses typically have higher PCVs?
A
Thoroughbreds (hot-blooded)
5
Q
What happens to neonatal PCV in horses?
A
Born with near adult values but it rrapidly decreases then returns to normal at around 18months
6
Q
T/F: More athletic animals have higher PCVs.
A
True
7
Q
What is a common finding in horse blood slides that may be pathologic in other animals?
A
Rouleaux formation
Do not confuse with agglutination
8
Q
T/F: Howel Jolly bodies are a normal finding in the horse.
A
True- 1-2% of RBCs
9
Q
What can be done to help “unstick” RBCs to differentiate agglutination and rouleaux?
A
Drop of saline on the slide
10
Q
T/F: Horses do not release reticulocytes into circulation
A
True- cannot accurately assess regenerative anemia
11
Q
What do you have to do to assess regeneration in the horse?
A
Bone marrow aspirates
12
Q
What are the two most antigenic blood systems in the horse?
A
Aa and Qa
No universal donor
13
Q
What are the clinical signs of anemia dependent on?
A
Rate and severity
14
Q
What will subtle anemia typically manifest with?
A
Exercise intolerance and poor performance due to decreased oxygen carrying capacity
15
Q
What will chronic anemia typically manifest with?
A
Some degree of regeneration and adaptation for low PCV
16
Q
T/F: Slowly developing anemia can get significantly lower than acute without development of clinical signs.
A
True
17
Q
What are the clinical signs of acute anemia?
A
o Poor performance o Lethargy/depression o Weakenss, tachycardia, tachypnea o Pale MM o Red-tinged, serum, red-tinged urine o Poor perfusion, shock syndrome o Collapse, seizures, death
18
Q
What are the clinical signs of chronic anemia?
A
Similar to acute but less severe due to adaptation to reduced PCV
19
Q
What can systolic murmurs be due to in anemia cases?
A
Decreased blood viscosity and increased turbulence
20
Q
Why do some cases of anemia present with fever?
A
If anemia is due to an infectious process
21
Q
What are the three general things that will lead to decreased PCV?
A
- Inadequate production
- Increased destruction
- RBC loss eg hemorrhage
22
Q
What is the most common cause of anemia in large animals?
A
Depression of RBC production due to chronic disease
23
Q
What are three things can can result in depression anemia?
A
- Vitamin/mineral deficiency
- Chronic/systemic disease
- Processes that damage bone marrow components (typically mild to moderate anemia)
24
Q
What is the most common cause of iron deficiency anemia in the horse?
A
Blood loss
Equine diets typically are very rich in iron and absorption issues are rare
25
What are three common causes of chronic blood loss leading to IDA?
1. Parasitism
2. Bleeding GIT lesions
3. Hemostatic defects
26
What is functional iron deficiency caused by?
Anemia of inflammatory or chronic disease
27
What is the pathogenesis of functional iron deficiency?
- Inhibition of iron release
- Defective marrow response to EPO
- Decreased RBC life span
28
What is the typical PCV range of a horse with functional iron deficiency?
Never less than 18-19%
29
Where is most of the iron in horses stored?
2/3 in the circulating RBC pool
The rest is in the liver, spleen, and bone marrow
30
What is the most common cause of anemia in the horse?
Anemia of inflammatory disease
31
How is the anemia characterized in anemia of inflammatory disease?
Mild to moderate non-responsive anemia with decreased serum iron and TIBC
PCV typically in the low 20s but can get down to 19%
32
What protein is responsible for transporting iron in the body?
Transferrin
Measured by evaluation of TIB
33
What is TIBC a measure of?
Derived from iron content of serum after total saturation of carrier protein
Gives an idea of the ability of the body to more iron
34
What does a decreased TIBC value tell you?
Proteins are unable to take up more iron aka decreased iron binding capacity
35
What is the treatment for true iron deficiency?
Iron supplementation
36
What is the only parenteral iron supplementation you can give in a horse?
Iron cacodylate
37
Why is iron dextran contraindicated in horses?
Possible anaphylaxis
38
T/F: Anemia of inflammation/chronic disease will not respond to clinical treatment.
True- iron supplementation has no effect
Must treat underlying disease not the anemia
39
How is anemia secondary to organ dysfunction characterized?
Mild to moderate nonresponsive anemia
40
What kind of organ/system dysfunction leads to anemia?
Chronic endocrine, renal, hepatic, or GIT disease
41
What is the typical pathogenesis of organ dysfunction anemia?
Bone marrow supression
Decrease in essential components, presence of toxic compounds, interference of normal EPO action/production
42
T/F: It is more important to treat anemia directly in organ dysfunction than the underlying cause since it can lead to severe anemia.
No. Never true. Always treat underlying cause.
Dummy.
43
What are two ways that EPO issues can mess with RBC production?
EPO deficiency due to renal disease/damage
Recombinant EPO dosing
44
What are the issues with EPO doping in horses?
Development of antibodies against the recombinant EPO that cross-react with the horses own EPO leading to life-threatening non-regenerative anemia that can only be treated with corticosteroids and transfusions
aka don't do this to your horse, it will die
45
What are the clinical signs of equine prioplasmosis/babesiosis?
Fever (102-107.6C)
Hemolytic anemia
Icterus, hemoglobinuria
Death
Generalized signs- depression, weakness, anorexia, incoordination, lacrimation, mucous nasal discharge, swelling of the eyelids
Greater incidence of hemoglobinuria and death with T. equi
46
What is anemia associated with in equine prioplasmosis/babesiosis?
Increased RBC destruction
47
How do you diagnose equine prioplasmosis/babesiosis?
Visualization of parasites on blood smear or detection of antibodies (within 14 days of infection)
48
How does the treatment for equine prioplasmosis/babesiosis differ from endemic to non-endemic areas?
Endemic- suppress clinical signs without eliminating organism from the animal
Non-endemic- completely eradicate organism from circulation
49
What drug is used to eradicate equine prioplasmosis/babesiosis and what are it's issues?
Iminocarb (cholinesterase inhibitor)
Side effects are colic and diarrhea
Can be fatal in donkeys
50
T/F: EIA is reportable.
True
aka Swamp fever
51
What is the epidemiology of EIA?
Lentivirus of the retroviridae familiy
Infects macrophages and integrates into host genome causing indirect destruction of RBCs
Vectors: Large biting flies, iatrogenic via needles and instruments; milk/semen possible but very rare
52
What are the clinical signs of EIA?
Anemia
Weight loss
Chronic illness
53
How do you diagnose EIA?
Gold standard: Coggins test- needed for USDA/APHIS international/interstate travel
ELISA: used to verify coggins test (false positives possible so recommended to use together)
54
How do you treat EIA?
You can't
55
What is the recommendation for horses infected with EIA?
Euthanasia and donation for research
Bodies must be marked with an A on the shoulder or neck
56
What can you do if the owner is unwilling to euthanize a horse infected with EIA?
Isolation 200yd away from other horses at all times
Double screened stalls
57
What is anemia associated with IMHA caused by?
Production of autologous antibodies against the animals own RBCS and hemolysis
58
T/F: IMHA can be either a primary or secondary process but is most commonly secondary due to an underlying primary disease process.
True
59
T/F: IMHA is often associated with destruction of thrombocytes as well.
True- not always accompanied but isn't a surprising finding
60
What are some primary diseases/conditions that can lead to IMHA?
* Virus – EIA
* Bacteria – C. perfringens
* Protozoa – Equine ehrlichiosis/Babesiosis
* Neoplasia – lymphosarcoma
* Drugs – penicillin, sulphas, phenylbutazone
* Immune mediated disease – purpura hemorrhagica or systemic lupus erythematosus
61
What are some initiating factors of IMHA?
Alteration of RBC membrane proteins
| Alterations to the immune system that will result in cross-reative antibodies
62
Is IMHA typically more associated with intravascular or extravascular hemolysis?
Extravascular hemolysis since complement activation is typically not strong enough to result in intravascular cell lysis
63
What is a hallmark RBC change of IMHA? Is it useful in the horse?
Spherocytes
Not useful in the horse since they don't have central depressions in their RBCs
64
What are the clinical signs of IMHA in the horse?
Variable degrees on anemia based on the primary process
Typically signs of extravascular hemolysis
PCV typically around 10-20%
65
How do you treat IMHA?
Treat primary process
If IMHA IS the primary process- corticosteroids only effective treatment (dexamethasone followed by prednisolone)
66
What are the three major causes of anemia due to blood loss?
Trauma, coagulopathies, infections
67
What are some specific causes of blood loss in the horse?
o Respiratory: guttural pouch, ethmoid hematoma
o Gastrointestinal: GI ulcers, parasitism, gastric squamous cell carcinoma
o Genitourinary: lacerations of vessels, middle uterine artery rupture, cystic calculi
o MSQ/cutaneous: trauma
o Coagulopathies: warfarin, liver disease, thrombocytopenia, congenital (hemophilia)
o Iatrogenic – post surgery: ethmoid hematoma, castrations
68
What are clinical signs of blood loss typically associate with?
Hypovolemia and diminished oxygen carrying capacity
69
What are some specific clinical signs associated with blood loss?
(Other than maybe finding a puddle of blood)
```
Pale MM
Lethargy, exercise intolerance, poor performance
Tachycardia
Tachypnea
Systolic heart murmur
```
70
What are clinical signs associated with blood loss due to thrombocytopenia?
Petechia, prolonged bleeding times, epistaxis
71
What are some things associated with clotting factor deficiency?
* Ecchymoses, hemarthrosis, hematoma
* Warfarin and sweet clover toxicity
* Liver failure
* Inherited coagulation deficiencies
72
T/F: DIC is never a primary disorder.
True- triggered by something else
73
T/F: In early stages of blood loss there is little to no change in PCV and TP.
True- makes it difficult to evaluate extent of hemorrhage
74
How does splenocontraction change presentation of blood loss anemia?
Will increase TP within 4-6 hours of contracion
Increase in PCV until about 12-24 hours when there will be an obvious reduction and will bottom out at 48hr
75
How often do you want to recheck PCV/TP in an bleeding horse?
Every 4 hours
76
How do you treat a bleeding horse?
- Fluid replacement with crystalloids
| - Transfusions
77
When is it appropriate to transfuse a horse with acute and chronic anemia?
Acute = PCV
78
Why do you wait longer to transfuse a horse with chronic anemia?
Because the horse will have adapted to the lower PCV and not be in as much trouble as the acutely bleeding horse
79
What do you need to be concerned about correcting in a horse with anemia?
1. Perfusion (circulating volume correction)
2. Maintenance of colume within vascular space
3. O2 carrying capacity
80
How long do transfused RBCs stay in circulating volume?
Avery of 5 days with a half life of 2 days
