Anemia Flashcards
What is anemia? What does it cause? How is it diagnosed?
decrease in red blood cell count or mass
decreased oxygenation of tissues —> clinical signs
PCV/HCT***, RBC count, Hgb concentration
What are the 7 common clinical signs of anemia?
- pale mucous membranes
- lethargy, decreased exercise tolerance
- increased CRT
- tachypnea
- dyspnea (shortness of breath)
- tachycardia
- murmurs caused by increased turbulence
What are 5 non-specific clinical signs of anemia? What are they most likely related to?
- weight loss
- fever
- lymphadenopathy
- polyuria
- polydipsia
underlying illness (that’s making the patient anemic)
What 3 clinical signs of anemia are associated with blood destruction?
- splenomegaly
- icterus (jaundice) of mucous membranes and skin
- hemoglobinuria - Hgb pigment, NOT entire RBC
How does duration of onset of anemia impact the severity of clinical signs?
SLOW onset —> less severe (may adapt to low oxygen levels)
RAPID onset —> more severe
What is the most common 3 step approach to assessing an anemic patient?
- LAB EVALUATION - red blood cell mass (PCV), mean cell volume, reticulocyte count, total protein
- HISTORY - accident leading to blood loss, medications
- PE - pale MM, lethargy
In what 3 ways is anemia classified?
- response of bone marrow - regenerative vs. non-regenerative
- RBC indices - MCV (size), MCHC (chromasia)
- pathophysiologic mechanisms - hemorrhage, accelerated RBC destruction by hemolysis, reduced or defective erythropoiesis
How do horses typically respond when undergoing regenerative anemia?
do not release reticulocytes - release macrocytes
What are the 2 major causes of regenerative anemia?
- blood loss - acute vs chronic
- blood destruction/hemolysis
What is the difference between acute and chronic blood loss causing regenerative anemia?
ACUTE = within hours + hypoproteinemia
CHRONIC = within several days-weeks + iron deficiency
How does acute blood loss present on the erythrogram?
- protein decreases with PCV and will usually return to normal within a week if bleeding is not ongoing
- normal erythrocyte morphology
When does erythrocyte morphology change if the patient is undergoing acute blood lose, making them anemic?
hemangiosarcoma (bleeding due to tumor rupture)
How does erythrocyte morphology change in the case of hemangiosarcoma?
acanthocytes + schistocytes
What are 4 common causes of acute blood loss?
- trauma and surgery
- coagulation disorders
- bleeding tumors (hemangiosarcoma)
- thrombocytopenia (<25,000/µL)
(blood loss does NOT cause thrombocytopenia)
What stimulates RBC production in bone marrow? What happens next?
erythropoietin (Epo)
new reticulocytes are sent into circulation within the next 3-5 days and mature within 1-2 days (7 days total)
What are 3 common causes of chronic blood loss?
(persistent, slow bleeding)
- GI ulcers
- bleeding GI tumor
- blood-consuming parasites: hookworms, whipworms
Where is it most common for chronic bleeding to occur?
intestines
What hookworm of the canine GI tract can cause anemia?
Ancylostoma caninum —> chronic bleeding
What are the causes of iron deficiency anemia in nursing animals and adults?
NURSING ANIMALS - inadequate intake
ADULTS - chronic blood loss
What are the 4 common lab findings in iron deficiency anemia?
- microcytosis of RBC and reticulocytes (decreased MCV)
- increased RDW (anisocytosis)
- normal MCHC
- thrombocytosis
Is iron deficiency anemia commonly regenerative or non-regenerative?
regenerative unless concurrent anemia of inflammatory disease
What is seen on a blood film in iron deficiency anemia?
keratocyte formation with increased central pallor