Lecture 8: Equine Hematology 1 and 2 Flashcards
What is anemia
decrease in RBC or hemoglobin (decrease oxygen carrying capacity of blood)
what hormone is essential for RBC production, where is it produced and in response to what
erythropoietin, produced in the kidney in response to hypoxemia
what causes anemia (3)
- Hemorrhage
- Destruction
- Decreased production
what are some physical exam signs of anemic patients
pale MM, tachycardia
what are some RBC parameters in anemic patients
- Decreased PCV
- Erythropoietin
- Decreased hemoglobin
horse presents to you with distal limb laceration affecting medial palmar digital artery that occurred about 1 hour ago. What would you expect PCV to be at this time
normal- not enough time for PCV to change
Patient anemic due to loss/hemorrhage, what do you expect plasma protein and bilirubin levels to be
plasma protein- low
Bilirubin- normal
patient Anemic due to destruction- what would you expect plasma protein, bilirubin and serum to be like
plasma protein- normal
Bilirubin- normal to increased
Serum hemolyzed
What are some causes of anemia due to destruction
immune mediated, infectious, toxicity
what are some causes of anemia due to decreased production
inflammation, toxicity/drugs, neoplasia, iron deficiency, genetic (fell pony syndrome
what is fell pony immunodeficiency syndrome
fatal disorder in dale ponies due to mutation in sodium/myo-inositol cotransporter gene (SLC5A3) causing progressive anemia and B cell lymphopenia (repeated infections)
case ex: you are treating a 10yr quarter horse gelding with pleuropneumonia. He has been in your hospital for a month and you have just run some updated blood work. His PCV is 26% (range: 35-52%).
What is your dx and what is your plan
Dx: anemia of chronic dz
Tx: treat pneumonia and monitor PCV
what is the relationship between inflammation and anemia
iron sequestration
what does the total iron binding capacity measure (TIBC)
indirect measure of transferrin concentration in serum
what is TIBC affected by
inflammatory state, liver iron stores, nutritional status/ protein intake
TIBC may be increased in horses with ___
iron deficiency
what is the formula for TIBC
UIBC (unbound) + iron
what is the % saturation for iron
percentage of transferrin that is saturated with iron
what is involved in the treatment of anemia
- Determine if transfusion is required
- Identify and treat underlying cause
perform blood transfusion when PCV <__% following acute blood loss
20%
perform blood transfusion when PCV <__% following chronic/slow blood loss
<12-15%
what is the transfusion procedure
- Find appropriate donor
2., determine how much blood is needed
3,. Perform transfusion
horses have >___blood cell antigens
30
horses have ___blood types
400,000
t or f: there is not universal blood donor for horses
true
what blood types are most antigenic
Aa and Qa
if you can’t blood type a horse and find a Aa negative or Qa negative what breeds should you choose
QH or standardbred gelding or gelding of same breed as patient
what is major cross matching
donor RBC’s + recipient plasma
what is minor cross matching
recipient RBCs + donor plasma
blood volume of a horse is __% of its body weight in kg
8%
500kg horse has __L of blood
40L
average healthy horse can donate __% of its blood volume
15-20%
What is the formula for determining amount of blood needed for transfusion
(PCV desired-PCV recipient) X (body weight in kg X 0.08)/ PCV donor
Case ex: perform transfusion on patient with PCV of 12%. Your patient is a 10yr old thoroughbred gelding who weighs 500kg. You would like to stabilize him with PCV of 20%. Cross matching not possible. Which of the following potential donors would you choose assuming they all have PCV of 38%:
A. 12 year old thoroughbred mare- 500kg
B. 6 year old standardbred gelding- 400kg
C. 8 year old QH gelding- 550kg
D. 7yr old Belgian mare- 900kg
How much blood would you take from donor. What is max your donor can give
C- 8year old QH gelding- 550kg
From donor: (20-12) (500x0.08)/ 38=8.421 8.4L
Max from donor: 550(0.08)=44, 44(0.20)=8.8L
how would you perform a blood transfusion
- Collect blood aseptically in collection bag with anticoagulant (ex: sodium citrate)
- Administer through blood set only
- 1mL/kg over first 30 mins
- 10-20ml/kg/hr
you give a transfusion and horses respiratory rate increases to 80bpm- what is happening and what do you do
transfusion reaction
1. Slow or stop transfusion
2. Diphenhydramine
what is the dose for epinephrine during anaphylaxis
0.005 to 0.02 ml/kg IV slowly of 1:1000 formulation
2.25-9mL for 450kg horse
what are some causes of thrombocytopenia in horses
- Immune mediated/ drug reactions
- DIC
- Endotoxemia/ septicemia
- EIA
- Anaplasma phagocytophila
- Lymphoma
- Alloimmunity
what are some clinical signs of thrombocytopenia
petechia, bleeding if below
what is treatment for thrombocytopenia
- Platelet transfusion if needed
- Identify and tx underlying cause
what drugs can cause immune mediated thrombocytopenia
penicillin, trimethoprim sulfamethoxazole
what is the tx for immune mediated anemia, thrombocytopenia
- Dexamethasone
- Prednisone
equine infectious anemia is a __virus transmitted by ___
lentivirus, tabanidae flies
what are some signs of equine infectious anemia
fever, anemia, thrombocytopenia
what is tx for equine infectious anemia
no treatment- either euthanasia or isolation at least 200 yards from other horses
what test should you perform on all patients with suspicious anemia
Coggins test
t or f: equine infectious anemia is a reportable dz
true
where does the organism for anaplasma pahgocytophila live inside the host
neutrophils (morulae)
what are some clinical signs of anaplasma phagocytophila
very high fever, depression, anorexia, weakness, edema
what are some bloodwork signs of anaplasma phagocytophila
mild, non-regenerative anemia, thrombocytopenia
horse presents with high fever, lethargy, and weakness. Perform a blood smear and see this- what is wrong
Anaplasma phagocytophila- morula in neutrophil
what is tx for Anaplasma phagocytophila
- Oxytetracycline IV
- Followed by doxycycline PO for 7-10 days
- NSAIDS if high fever
what Protozoa are involved in equine piroplasmosis
- Babesia caballi
- Theileria equi
what clinical signs and blood work findings are seen with equine piroplasmosis
Intra/extravascular hemolysis, fever, edema, coagulopathies, thrombocytopenia, hemoglobinuria
what is tx for equine piroplasmosis
imidocarb
you administer Oxytetracycline IV too patient to tx Anaplasma phagocytophila and they suddenly collapse- what happened and what do you do
giving Oxytetracycline too fast can diminish calcium and cause them to collapse
Administer calcium
