Anemia Flashcards
What are the 3 mechanisms of anemia?
Increased loss (hemorrhage)
Increased destruction (hemolysis)
Decreased production by marrow
Anemia is a reduction of red blood cell mass, resulting in _______ ______ of tissues.
decreased oxygenation
Since HCT can have calculation errors, what are more accurate ways to measure the red cell mass?
PCV HG concentration
A dog presents to your clinic for lethargy and exercise intolerance. On exam, you find that the dog is dyspneic, has pale mm, and an increased heart rate. There is no history of a heart murmur in the past, although you auscultated one today. What is likely the cause of the new murmur?
Anemia with PVC <20% (due to increased turbulence)
Non specific signs of anemia, such as weight loss, fever, lymphadenopathy, and PU/PD, can also be seen with kidney disease. How could you differentiate the two?
Kidney disease will show an increased BUN and creatinine, and very low urine SG (inability to concentrate urine)
A 2 year old dog is brought in for extreme lethargy and urinating blood. RR-68, T-103.4, P-220. The dog is icteric, and you are able to palpate the spleen, which is enlarged. PCV = 28 (35-45), TP = 7.5 (6.5-8). What is the likely mechanism of anemia in this dog?
Blood destruction
Signs will include splenomegaly, icterus, and hemoglobinuria. PCV will be low, indicating anemia, but the total protein will be within normal range.
In patients with a rapid onset anemia, clinical signs are (less/more) severe than with slow onset anemia.
more severe
What are the main aspects of the CBC needed for diagnosing anemia?
PCV (red blood cell mass)
MCV Reticulocyte count
Total protein
T/F: Total protein will be low in patients with acute and chronic anemia.
FALSE. Chronic anemias may show normal protein levels
Bixby is a 6 year old MN Golden Retriever with a PCV of 26. The owner has just informed you that over the past couple months, Bixby has had periodic episodes of weakness. What does this put on your differential?
Can indicate internal blood loss (hemangiosarcoma), or an insulinoma.
In acute anemia cases, erythrocyte morphology is usually normal. What is the exception to this and what changes would you expect to see?
Hemangiosarcoma
You would see acanthocytes, schistocytes, nRBCs and mesothelial cells.
What are some examples of acute blood loss?
Trauma/Surgery
Coagulation disorders (inherited or acquired)
Bleeding tumors
Thrombocytopenia (if PLT conc less than 10k)
T/F: Blood loss will cause thrombocytopenia.
FALSE - unusual to find PLT conc less than 100k from blood loss.
What is the most common route of blood loss in chronic anemia?
Via the intestine
What are some examples of chronic blood loss?
GI ulcer
Bleeding GI tumor
Blood consuming parasites
Inadequate intake in babies and chronic blood loss in adults can lead to __________ anemia.
Fe++ deficiency anemia
A lethargic 4 year old goat with pale mm has a PCV of 18% and a MCHC within normal range. The MCV histogram shows a left shift and the blood film shows keratocytes and increased central pallor of RBCs, with marked thrombocytosis. What could be the cause of anemia in this goat?
Fe++ deficient pastures or intestinal parasites (Iron deficiency anemia)
You suspect iron deficiency anemia in a cat. What changes would you expect to see in serum iron concentration, transferrin saturation, and ferritin or hemosiderin (storage iron) concentrations?
Serum iron: decreased
Transferrin: decreased
Ferritin/hemosiderin: decreased
In Fe++ deficiency anemia, what value will be normal in dogs and cats, but increased in other species?
Total iron binding capacity
Treating iron deficiency anemia in adults involves finding the source of blood loss. In neonates, iron is supplemented. What is the acceptable route of supplement administration?
Iron injections (oral supplements will not work!)
MCV histogram on an anemic shih-tzu with a portosystemic shunt shows a left shift. Is it safe to assume the anemia is from iron deficiency?
NO! Both portosystemic shunts and Chinese dog breeds are risk factors for microcytosis on their own.
T/F: Like in humans, anemia of inflammatory disease in dogs causes microcytosis.
FALSE
Anemia of inflammatory disease in dogs is usually normocytic and will have increased storage iron (ferritin/hemosiderin).
You prepare this blood sample on a dog with a PCV of 25%. What kind of anemia are you suspecting?
Iron deficiency
(thrombocytosis, keratocytes, increased central pallor, large platelets)
A 10 year old Labrador with periodic weakness and recent anemia has markedly increased reticulocytes and decreased HG. You suspect iron deficiency anemia. The blood film shows acanthocytes and schistocytes. You request a liver aspirate and discover these double-nucleated connective tissue cells with large nucleoli. What is the probable cause of anemia in this dog?
Hemangiosarcoma
A 1 year old dog presents to your clinic with microcytic anemia, vomiting, and abdominal pain. Past medications include steroids and antibiotics. What is a potential cause for iron deficiency anemia in this dog?
Gastric perforation secondary to ulcer (steroid treatment?)
IMHA, Heinz body anemia, RBC parasites, zinc toxicosis, inherited RBC enzyme deficiencies, and hypophosphatemia all cause:
blood destruction
IMHA is often secondary to:
infection
mod live virus vaccination
neoplasia (lymphoma)
drugs
Penicillin, cephalosporins, trimethoprim-sulfa, and levamisole are drugs implicated in causing _____.
IMHA
Factors linked to the onset of IMHA in equids:
Penicillin
Clostridial infections
Neoplasia
What can cause IMHA in cats?
Mycoplasma haemofelis
FeLV
neoplasia
What dogs are at a higher risk for developing IMHA?
Cocker Spaniels!
Poodles, Collies, Border Collies
Females
Middle aged - Old
A bone marrow aspirate on an dog with pale mm and enlarged spleen shows macrophages phagocytosing many RBCs. What is causing anemia in this dog?
IMHA
*extravascular hemolysis
You prepare a blood film on an icteric dog and see that the background of the slide looks more pink than usual, and that most of the RBCs are ghost cells. What kind of hemolysis is taking place?
Intravascular
*pink background is free HG and ghost cells are a result of HG loss
An icteric 7 year old female Cocker Spaniel in your care is urinating blood and has an enlarged spleen. The dog recently received a modified live vaccination, and you suspect IMHA, but the blood film isn’t showing spherocytes or agglutination. What test can you use to confirm IMHA in this case?
Coomb’s test.
*Contains Ab specifically against IgG to allow agglutination when there otherwise wouldn’t be any.
Disadvantages of the Coombs test:
Many false positives (cats especially)
Many false negatives
In cases of IMHA involving thrombocytopenia, a negative DIC test will suggest what other diease?
Evan’s Syndrome
Chemistry on a dog with suspected IMHA shows increased creatinine and BUN. What type of leukogram do you expect to see to confirm your diagnosis?
Inflammatory
Although spherocytosis can implicate IMHA, what other causes should be on you diffferential?
Previous mismatched blood transfusion
Rattlesnake evenomation
Heinz body anemia in horses
Zinc toxicosis
Bee stings
What is the most common cause of death with IMHA?
Thromboembolism