What type of clinical presentation do animals with acute, severe hemorrhage show?
- SHOCK
- low BP, tachycardia, tachypnea
- pale MM & prolonged CT
- poor peripheral pulses & cool extremities
- trembling, weakness, depression
With acute blood loss, how long does it take for anemia to become clinically important?
12-24 hours
What clinical signs are associated with anemia?
- pale MM
- tachycardia/tachypnea
- weakness/exercise intolerance
- anorexia/depression
- physiological heart murmur
What is a good indicator of regeneration in the horse?
MCV > 60 fl
Common causes of hemorrhage in the horse
- uterine rupture (pregnant mares, late gestation)
- NSAID toxicity
- renal medullary necrosis
- GI bleeding
- exercise-induced pulmonary hemorrhage
- guttural pouch mycosis (internal carotid rupture)
- trauma (internal or external hemorrhage)
- coagulopathy
When do TP & PCV changes occur after an acute blood loss event?
- TP-4-6 hours after
*may not drop significantly if internal bleeding - PCV-12-18 hours after
What bloodwork findings are evidence of acute blood loss anemia?
regenerative anemia & hypoproteinemia without evidence of hemolysis
Appropriate diagnostic steps if hemorrhage suspected but not evident externally
- peritoneal or abdominocentesis
- thoracic or abdominal US
- rectal examination
- endoscopy
- fecal occult blood
- urinalysis
Hemorrhage is what kind of fluid loss?
isotonic
Why should acepromazine be avoided in horses with acute blood loss?
Don’t use in hypotensive animals because it reduces peripheral vasoconstrictive response
What is one potential reason to avoid colloids in a hemorrhage situation?
colloids can inhibit coagulation, so be careful using unless positive that bleeding is controlled
Fluid support for horse that suffered hemorrhage and is in shock
- Hypertonic fluids first (5% NaCl)
- follow with isotonic fluids (LRS)
When is a blood transfusion warranted in hemorrhage situations?
- PCV<15 if acute
- PCV<8-10 if chronic
- HR>90 een after circulatory support
- PCV decreases to <20% in 12 hours
Describe the ideal universal blood donor
- non-thoroughbred
- gelding
- Aa, Qa, and Ca-negative
What is the lifespan of transfused RBCs?
2-5 days
After treating an acute hemorrage, horses should rest until PCV is ______
>20%
What causes clinical signs seen with chronic hemorrhage?
poor oxygen delivery
What findings provide evidence of iron deficiency?
- non-regenerative anemia
- LOW serum iron concentration
- LOW serum transferrin saturation
- HIGH iron-binding capacity ‘
What is the pathophysiology of chronic hemorrhage?
- bone marrow suppression d/t underlying disease
- bone marrow failure
- iron deficiency anemia may be factor
What is the focus of treatment for chronic hemorrhage?
treat the underlying cause
What is the dominant clinical picture of chronic hemorrhage?
Anemia
- pale MM
- tachycardia/tachypnea
- weakness/exercise intolerance
- anorexia/depression
- physiological heart murmur
Differentials for chronic anemia
- chronic blood loss (iron deficiency)
- underlying disease (anemia of chronic disease or inflammation)
- EPO administration
- aplastic anemia
Oral iron should not be given to what age horses?
neonates (2-3 weeks)-Hepatotoxic
What findings are used to diagnose hemolytic diseases?
- anemia with normal plasma protein, hyperbilirubinemia, hemoglobinemia, and/or hemoglobinuria
- altered RBC morphology (spherocytes, eccentrocytes, Heinze bodies, etc.)
