Anemia/cell inclusions/parasites

Question 1

anemia

Answer 1

absolute decrease in PCV, Hg concentration, and/or RBC count
clinical sign of disease, not a diagnosis

Question 2

MCV in anemia

Answer 2

mean corpuscular volume, RBC size
normocytic, macrocytic, microcytic

Question 3

MCHC in anemia

Answer 3

mean corpuscular hemoglobin concentration, Hg concentration
normochromic or hypochromic

Question 4

how is anemia classified?

Answer 4

by RBC size and Hg concentration
then we look at bone marrow response and see if we have certain mechanisms occurring that are causing anemia

Question 5

causes of anemia

Answer 5

blood loss/hemorrhage
this can happen from trauma, surgery, GI ulcers, hemostatic defects (DIC, rodenticide, sweet clover toxicosis), parasitism, neoplasia, vitamin K deficiency

Question 6

possible clinical signs of anemia

Answer 6

tachycardia, tachypnea

Question 7

what happens in the body as anemia sets in?

Answer 7

PCV is initially within reference range because all blood components will be equally lost (plasma and cells)
splenic contraction occurs as body starts to try to compensate
interstitial fluids shift in and out of cells to try to increase BP and blood volume, this dilutes red cell mass = PCV, Hg, RBC count decreases = anemia, low protein

Question 8

how are signs of anemia seen in chronic blood loss?

Answer 8

slower signs of anemia because the body adapts

Question 9

RBC indices

Answer 9

MCV, MCH, MCHC, RDW
RDW = red cell distribution width: variation in size and volume

Question 10

hemolysis (IMHA)

Answer 10

hallmarks: spherocytosis, autoagglutination, positive Coombs test (antibodies against RBCs)
hemolysis is usually immune mediated but can be caused by toxins or infections

Question 11

reduced/defective erythropoiesis

Answer 11

can be caused by bone marrow damage, neoplasia, chronic renal disease, or infection

Question 12

bone marrow damage reduced/defective erythropoiesis signs

Answer 12

non-regenerative anemia and pancytopenia (granulocytes affected first, then platelets, then RBCs)

Question 13

neoplasia caused reduced/defective erythropoiesis

Answer 13

caused by blood loss from bleeding tumors or effects on bone marrow

Question 14

which infections can cause reduced/defective erythropoiesis?

Answer 14

Ehrlichia, FeLV, feline panleukopenia, parvo

Question 15

regenerative anemia

Answer 15

bone marrow responding to demand
increased MCV (macrocytosis or anisocytosis), basophilic erythrocytes, higher amount of RNA released from bone marrow with lower number of reticuloytes

Question 16

retic count

Answer 16

polychromatophils in NMB
cats: only count aggregate
reticulocytosis = regenerative anemia

Question 17

basophilic stippling

Answer 17

punctate aggregates of RNA
shows regeneration in bovids
dogs/cats: basophilic stippling but minimal polychromasia could be lead toxicity (> 10 nRBCs/100 cell diff)

Question 18

aggregate vs punctate

Answer 18

aggregate is like clumps of residual RNA
punctate is like little dots of RNA, aggregate broken up, aka basophilic stippling
punctate more mature

Question 19

how do you perform a retic count?

Answer 19

1. mix together fresh blood and NMB
2. incubate for at least 15 minutes
3. make a blood smear
4. look under microscope to obtain % of retics in 10 fields (# of retics divided by 1000 multiplied by 100)

Question 20

what is the one animal you can’t do a retic count for?

Answer 20

horses because they don’t release retics from the bone marrow
maturation is confined to bone marrow

Question 21

how do you calculate corrected retic count?

Answer 21

retic % times observed PCV/HCT divided by normal PCV/HCT

Question 22

what is the normal PCV/HCT in dogs and cats?

Answer 22

dogs: 45%
cats: 37%

Question 23

how do you calculate absolute retic count?

Answer 23

retic % (converted to a decimal) times total RBC count/uL

Question 24

reticulocyte production idex (RPI)

Answer 24

usually used in human med, can only be applied to dogs because we have lack of information for other species
corrected retic % divided by maturation time based on observed HCT

Question 25

retic maturation index

Answer 25

HCT: 45% = 1x faster maturation HCT: 35% = 1.4x faster maturation HCT: 25% = 2x faster maturation HCT: 15% = 2.5x faster maturation

Question 26

polycythemia

Answer 26

increased circulating RBCs causes: relative or absolute

Question 27

relative polycythemia

Answer 27

dehydration cause most common polycythemia will have increased TP and HCT as well

Question 28

absolute polycythemia

Answer 28

true polycythemia 1. primary: polycythemia vera = very rare, dogs/cats may have RBC population of 65-75%, blood becomes thick and has difficulty moving through small vessels = fewer nutrients and O2 delivered, animals feel tired, sluggish, weak, seizures 2. secondary: compensatory response (appropriate response) = body responding to reduced oxygenation of tissues, usually compensating for heart disease or pneumonia 3. inappropriate response = renal disease, kidneys can cause increased erythropoietin release

Question 29

Howell-Jolly bodies

Answer 29

nuclear remnants normal in low numbers in cats and horses sign of regenerative anemia seen in animals that had a splenectomy since the spleen removes these normally

Question 30

heinz bodies

Answer 30

cats most common round angular retractile bodies - confirm on NMB denatured Hg caused by toxicity: onions, acetaminophen, propylene glycol disease causing: diabetes mellitus, hyperthyroidism 40% of cats with increased amounts is usually from metabolic disease: diabetes, pancreatitis (ketones damaging Hg) "old cat dz"

Question 31

eccentrocytes

Answer 31

hemoglobin pushed to the side same as heinz bodies

Question 32

barr body

Answer 32

pyknotic inactive remains of 1 of the 2 X chromosomes low numbers seen in neutrophils of normal female animals

Question 33

Babesia canis

Answer 33

protozoan hemoparasite large form tick vector affects large animals causes hemolytic anemia pear shaped droplets or pyramid shaped with pinpoint magenta center

Question 34

Babesia gibsoni

Answer 34

protozoan hemoparasite cignet ring shape, harder to see than Babesia canis common in US causes hemolytic anemia and thrombocytopenia small form very serious strain in pit bulls and greyhounds through bites (breeds used for racing/fighting) bites or vertical transmission PCR testing available single, paired, or tetrad oval inclusions usually on feathered edge

Question 35

piroplasmosis

Answer 35

protozoan hemoparasite seen in equids: horses, donkeys, zebras tick vector USDA reportable we are free of this disease 50% mortality

Question 36

cytauxzoon felis

Answer 36

protozoan hemoparasite tick transmission: commonly lone star tick causes non-regenerative hemolytic anemia: usually thrombosis will cause fatality, some virulence variability (some survival in Arkansas cats unexplained) fatal same look as small form babesia bobcat reservoir host infection more likely in cats not receiving prophylaxis PCR testing available

Question 37

cytauxzoon felis CS

Answer 37

reduced appetite, followed rapidly by anorexia, lethargy, sometimes vocalization (interpreted to be pain or discomfort) usually see pronounced fever

Question 38

hepatazoon

Answer 38

protozoan hemoparasite affects WBCs classified as H. americanum: causes severe disease American canine hepatazoonosis (ACH): causes mild disease in other areas of world ACH is an EID (emerging infectious disease): severe disease in Gulf Coast caused by ingestion of infected ticks fatal if untreated gamonts = large oblong structure displaces nucleus

Question 39

hemoproteus

Answer 39

RBC protozoan of wild birds "hugs" RBC nucleus CS vary by species frequently causes fatalities in pigeons and doves

Question 40

leucocytozoon

Answer 40

protozoan infects RBC and WBC distorts cell "loco": gametocytes distort host cell elongating and distending cell arthropod vector causes mild to severe anemia

Question 41

plasmodium

Answer 41

protozoan hemoparasite avian malaria "pushy sausage" (displaces RBC nucleus) mosquito vector causes anemia related species causes disease in reptiles, mammals, humans in tropical areas gametes in RBC cause nuclear displacement

Question 42

hemogregarines

Answer 42

protozoan hemoparasite affects RBCs affects reptiles especially snakes sausage shaped gametes in cytoplasm of RBCs which displaces nucleus usually non-pathogenic but increased stress can increase infection and cause mortality

Question 43

trypanasomes

Answer 43

protozoan hemoparasite seen in tropics: sleeping sickness elongated, flagellated protozoans extracellular cattle, sheep, wild birds, reptiles, fish affected pathogenic and non-pathogenic strains (usually non-pathogenic in US) Chagas (American trypanosomiasis): T. cruzi: seen in the South zoonotic transmitted by kissing bug or eating infected bugs/rodents causes heart failure

Question 44

hemotrophic mycoplasma

Answer 44

bacteria hemoparasite hemofelis/hemocanis hemobartonella arthropod vector (fleas), vertical or direct transmission can detach from RBC: PCR test cocci-like: smallest free-living microorganism dogs don't typically develop disease unless they had a splenectomy huge variety: some can infect humans, only some cause clinical illness but seeing more outbreaks in sheep, cattle, pigs causes agglutination/IMHA in symptomatic animals and mild to fatal anemia in cats (feline infectious anemia: FIA)

Question 45

anaplasma

Answer 45

bacteria hemoparasite looks like mycoplasma high prevalence in cattle globally: A. marginale tickborne causes fatal hemolytic anemia dogs responsive to treatment of antibiotics or can be asymptomatic up to 50% mortality

Question 46

rickettsial

Answer 46

somewhere between bacteria and virus

Question 47

ehrlichia canis

Answer 47

rickettsial hemoparasite one of the most common blood parasites in small animals affects neutrophils during acute infection and then moves into monocytes tick transmission: Rhipicephalus (brown dog tick) packets of morulae (bacterial organisms) seen in RBCs can affect dogs, horses, llama, cats CS: thrombocytopenia, fever, lethargy, renal failure

Question 48

distemper

Answer 48

viral variable in size and stain pink to light purple highly contagious, widespread throughout US in wild carnivores

Question 49

microfilaria (dirofilaria)

Answer 49

extracellular large! round head and tapered tail dark purple stippled internal organs