Chapter 108 - anemia Flashcards
Animals with haemolysis usually have hyperbilirubinema & hyperbilirubinuria, with or without hemoglobinemia or hemoglobinuria. T/F?
T
What demographic data will let you rule out haemophilia A and B in a patient?
X-linked recessive, affects males only
How does anaemia trigger tachypnoea?
acidemia and/or hypoxemia –> stimulation of carotid body chemoreceptors –> increased respiratory rate
What is the most common hereditary coagulopathy in cats? Clinical significance?
Factor XII deficiency - does not cause clinical bleeding
At what serum bilirubin concentration is visible icterus expected?
2mg/dL
Why is cyanosis less likely to be seen in anaemic hypoxic animals?
Cyanosis requires 5g/dL of unoxygenated Hb. If PCV = 15, will need to be 100% deoxygenated.
Hb (g/dL) x 3 ~= Hct.
What compensatory mechanisms occur with acute tissue hypoxia?
- selective peripheral vasoconstriction: shunting of blood from skin etc to brain, kidney, heart
- augmented cardiac output (increased HR & SV initially, followed by cardiomegaly) - mild systolic basilar murmur may be heard
- R shift in the Hb-O2 dissociation curve due to increased metabolic acidity (Bohr effect; dogs & cats) & increased conc of 2,3-diphosphoglyceride (dogs) –> reduced Hb-O2 affinity
- decreased activity
- erythropoietin-mediated accelerated erythropoiesis (takes 5-7 days for maximal effect)
An absolute reticulocyte of less than what indicates a non-regenerative anaemia?
40,000/mcL
Why are nRBCs a poor parameter for assessing regeneration in small animals?
non-specific - also seen with lead poisoning, sepsis, heatstroke, neoplasia (esp HSA), hyperadrenocorticism
1 platelet/HPF (high power field) = ~how many peripheral platelets?
15,000/mcL
How many platelets are expected per HPF in a normal dog blood smear (non-grey)
8-15
How many neutrophils should be seen per HPF in a normal dog?
should be ~1 per 3 HPFs
How does hypophosphataemia cause haemolysis?
Depletion of ATP and 2,3-DPG leads to spherocytosis, red cell membrane rigidity and shorted survival.
At what level of hypophosphataemia is haemolysis expected?
severe - <1mg/dL
Hereditary factor VII deficiency has been reported in which breeds? Clinical significance?
Beagles, Alaskan Klee Kais, Scottish Deerhounds - mild bleeding tendency
Describe the clinical relevance of PIVKA (proteins
induced by vitamin K antagonism or absence) testing in suspected rodenticide toxicity?
Modified PT test, neither more sensitive or specific cf PT - no additional diagnostic value
List 2 tests to screen for vWD
ELISA
BMBT
What platelet count is needed to confirm thrombocytopathia with BMBT? i.e. avoid false positives
100,000/mcL
Anemic tachypneic animals with cardiovascular instability may benefit from O2 therapy. T/F?
T
First line treatment for minor bleeding in a dog with vWD?
Desmopressin 1-4mcg/kg SC q3-4h
Only if type 1 or mild type 2
Why are animals with chronic but decompensated anaemia at risk of volume overload with transfusion?
Generally normovolemic with maximal compensatory HR/SV +/- cardiomegaly
What metal intoxication can lead to anemia?
Zinc and copper
Give examples of infectious diseases associated with anemia in dogs? cats?
Dogs: babesia, ehrlichia, anaplasma, mycoplasma, leishmania, leptospira
Cats: FIV, FeLV, FIP, mycoplasma, cytauxzoon felis
What is the the most consistent RBC change with chronic anemia (non-aplastic)?
Hypochromasia
Autoagglutination is very specific for IMHA. T/F
F. It could be caused by formation of rouleaux
