lecture 4 - extravascular hemolysis

Question 1

(extravascular hemolysis)

1. RBCs removed from bloodstream by what?
2. get an increase in what?

Answer 1

1. splenic + hepatic phags
2. unconjugated bilirubin

Question 2

(neonatal isoerythrolysis)

1. what is it?
2. why does mare produce antibodies?
3. where does foal get antigen from?
4. where does foal get alloantibodies from?
5. what breeds usually affected?
6. what text used for dx?

Answer 2

1. blood group incompatibility between dam & foal/calf

(alloantibodies in dam’s colostrum directed against foal RBC alloantigens)

2. transfusions/previous birth
3. sire
4. mare’s colostrum
5. standard and thorough bred
6. jaundice foal agglutination test

Question 3

1. Neonatal Isoerythrolysis is calves is almost always what?

Answer 3

1. iatrogenic

(Eg cows immunized with RBC-containing vaccins during pregnancy)
(Occurs when calf RBCs carry the same “foreign” alloantigens as vaccine RBCs)

Question 4

(Immune Mediated Hemolytic Anemia)

1. What is the difference between 1° and 2° IMHA?
2. How to Dx?
3. tx for 2°?

for 1°?

Answer 4

1. 1° = self-antigens on RBC recognized as foreign by immune system

2° = immune system reacts to barcterial/viral/etc antigens on RBC membranes

2. coombs test (lots of false +/-)

dx of exclusion

3. remove underlying

corticosteroids (some may need stronger ie chemoterapeutics)

Question 5

(equine anaplasmosis)

1. what vector
2. what bacteria
3. how long is incubation?
4. see what on CBC?

when can you see morulae in neutrophils+/-eosinophils?

5. dx?
6. tx of choice?

Answer 5

1. deer ticks (ixodes)
2. anaplasma phagocytophila
3. 1-9 days with natural infection
4. leukopenia, neutropenia, thrombocytopenia, mild anemia

3-5 days

5. intracellular morulae (early)

PCR (5 days)

seroconversion (4x higher in 2 wks)

6. oxytetracycline

Question 6

(ruminant anaplasmosis)

1. vector?
2. what bacteria affects cattle and wild ruminants?

sheep and goats?

3. source of infection?
4. fatality worse in old or young?
5. anemia due to what?
6. dx?
7. tx?

Answer 6

1. arthropod (ticks and flies)
2. anaplasma marginale

anaplasma ovis

3. blood of infected animals

(if recover - carriers for life! = major reservoirs)

4. old!
5. direct dmg from bac and 2° immune dmg
6. dot-like inclusion bodies on RBC margins
7. oxytetracycline

Question 7

(Equine Infectious Anemia)

1. retrovirus related to what?
2. what hinders eradication?
3. tx?
4. vx?

Answer 7

1. HIV
2. persistent infections
3. no
4. no

Question 8

(mycoplasma hemollama)

1. rickettsial parasite of camelids
2. how often does it cause dz?

Answer 8

2. rarley