L33: anemia and thrombocytopenia

what organ in the body detects low oxygen?

kidney → will produce EPO

what is the lifespan of a RBC in a dog?

120 days

what is the lifespan of a RBC in a cat?

60 days

what organ gets rid of old/abnormal cells?

spleen

what organ recycles iron and bilirubin?

liver

how long does it take for RBC to be made?

3-4 days

what does RBC synthesis require?

GI absorption of folate, B12, and iron

what is the number one indicator for regenerative anemia?

recticulocytosis

what number of reticulocytes would indicate regenerative anemia in dogs?

more than 100,000

what number of reticulocytes would indicate regenerative anemia in cats?

40,000-60,000

what parameters will you see to indicate that the cause of anemia is whole blood loss?

1. decreased protein

2. PCV and TS both decrease together

what parameters will you see to indicate that the cause of anemia is increased destruction (hemolysis)?

1. proteins WRI or increased

2. PCV and TS values go in opposite directions (one increase, other decrease)

what are the causes of whole blood loss?

1. external bleeding

2. internal bleeding

what areas do we tend to see external bleeding that lead to whole blood loss?

1. GIT

2. urinary tract

3. wounds

4. petichae

what areas do we tend to see internal bleeding that lead to whole blood loss?

1. body cavity → pleural, peritoneal, pericardial

2. into a mass or abscess

what should you do if you see fluid in an anemic patient?

tap it and put into a non-coagulant tube

what does it mean if blood does not clot in an anemic patient after putting it in a blood tube?

hemorrhagic effusion

what should you do with the PCV of the fluid from the anemic patient you sampled?

compare to peripheral PCV

what type of bleeds are associated with primary hemostasis?

small surface bleeds

what clinical signs are associated with primary hemostasis?

1. petechiae

2. ecchymosis

3. melena

4. epistaxis

what type of bleed is associated with secondary hemostasis?

large cavity bleeds

what are causes of decreased production for anemia?

1. anemia of chronic or inflammatory disease

2. renal disease

3. bone marrow disease

4. iron deficiency

what categories of bone marrow diseases can lead to decreased production of RBC leading to anemia?

1. infectious

2. immune-mediated

3. toxin leading to fibrosis or necrosis

4. neoplasia

5. myelodystplastic syndromes (MDS)

what infectious agents can lead to infectious bone marrow disease?

1. Erlichia

2. FeLV

what is an example of a toxin that will lead to fibrosis and necrosis of bone marrow?

estrogen

what is the most common neoplasia of bone marrow?

lymphoma

what is MDS secondary to for bone marrow diseases?

1. infection

2. IMHA

3. toxins

when is a bone marrow aspirate indicated?

1. multiple cell lines affected and not regenerating

2. neoplasia suspected

what signs would make you think that there is neoplasia of bone marrow?

1. hypercalcemia

2. hyperglobinemia

3. abnormal lymphocytes in circulation

what signs would you think that multiple cell lines are affected and bone marrow is not regenerating?

1. non-regenerative anemia

2. neutropenia

3. thrombocytopenia

what are the risks of bone marrow aspirate?

1. bone fracture

2. introducing infection to skin

what cellular things can indicate regenerative anemia caused by hemolysis?

1. spherocytes

2. elevated bilirubin

3. reticulcytosis

4. polychromasia

5. anisocytosis

what dog breed is 8 times more likely to develop IMHA?

Cocker Spaniels

what transfusion product is best in a dog that has anemia due to hemolysis?

pRBC

what causes hemolysis?

1. infections

2. oxidative stress

3. toxins

4. immune mediated

5. RBC membrane damage

6. hemophagocytic syndromes (rare)

7. RBC fragility (rare)

what things can cause RBC membrane damage?

1. DIC

2. heat stroke

3. vascular disease

what toxins can lead to increased destruction of RBC leading to anemia?

1. metals

2. onions

3. garlic

4. hyperphosphotemia due to refeeding syndrome

what imaging do we want to do if we suspect anemia from increased destruction of RBC?

1. abdomen radiographs

2. thoracic radiogrpahs

3. ultrasound spleen

what can mimic intravascular hemolysis on radiographs?

pennies → ESPECIALLY IN PUPPIES

what is the difference for rouleau and agglutination on blood smear?

• rouleuax → stacks of red blood cells

• agglutination → cells stuck to one another

what test can we use to look for agglutination?

saline agglutination test

why will we not use a coomb’s test if an animal already has IMHA?

test will always be positive due to existing antibodies

what are the common causes of a primary hemostatic defect?

1. not enough platelets (most common)

2. platelets not working

3. vascular disorder

what are the causes of secondary hemostatic defect?

1. vitamin K problem → rodenticide, liver disease

2. coagulation factor deficiency

what do we do if a patient has a CBC with low platelets and petechiae?

thrombocytopenia work up

how can we estimate platelets on a blood smear?

platelets in monolayer per high power field * 10000-15000

spontaneous bleeding occurs when platelets are less than…

40,000

what is shown in the image?

platelet clumping

what is shown in the image?

blood clot → do not put in machine to read!

what should be done first for platelet testing?

platelet count

where do we start looking for thrombopathies in platelet testing?

assessing platelet function

how do we categorize the thrombocytopenia?

1. consumption

2. increased destruction

3. decreased production

what are the causes of platelet vasculitis?

1. infection

2. heat stroke

3. SIRS

4. sepsis

5. DIC

what are the causes of increased destruction of platelets?

1. infection

2. immune mediated

3. drugs or toxins

what infections lead to increased destruction of platelets?

1. anaplasma

2. rickettsia

3. leishmania

what leads to decreased production of platelets?

bone marrow disease

what do we look for if we think thrombocytopenia is due to platelet consumption?

look for evidence of internal or external bleeding → physical exam, imaging, or coags

what are common triggers of immune mediated thrombocytopenia?

1. infection

2. neoplasia

3. sulfa drugs

4. recent vaccinations

what infectious agents can cause immune mediated thrombocytopenia?

1. E. canis

2. anaplasma

3. babesia

4. leishmania

what drug can we consider giving to stop platelet destruction?

vinicristine

if an animal is anemic and has thrombocytopenia, what should we give them if they need a transfusion?

whole blood

what should we not do if a patient has thrombocytopenia?

1. no jugular sticks

2. no nasal feeding tubes

3. no cystocentesis