PATHOLOGY - Bovine Anaemia

Question 1

What are the three most common causes of anaemia in cattle?

Answer 1

Haemorrhage
Infectious agents
Toxicity

Question 2

What are five common causes of haemorrhage in cattle?

Answer 2

Trauma
Castration
Dehorning
Obstetric haemorrhage
Abomasal ulceration

Question 3

What are three common traumatic causes of haemorrhage in cattle?

Answer 3

Trauma to the udder
Ruptured middle uterine artery
Epistaxis due to caudal vena caval syndrome

Question 4

What is the average blood volume for cattle?

Answer 4

55ml/kg blood volume

Question 5

How can you calculate the allowable blood loss in cattle?

Answer 5

Allowable blood loss = Estimated blood volume x (Initial PCV - minimum PCV) / Initial PCV

Use 35% PCV for the initial PCV and 20% for the minimum PCV

Question 6

What is a normal PCV in cattle?

Answer 6

A normal PCV in cattle is above or equal to 24%

Question 7

What can you use to manage haemorrhage in cattle?

Answer 7

Intravenous and oral fluid therapy
Blood transfusion

Question 8

(T/F) You do not need to cross-match before transfusing blood to cattle

Answer 8

TRUE. Though cattle have a wide range of blood types, there is a very low risk of immunological haemolytic transfusion reactions so cross-matching is unnecessary

Question 9

What should you be aware of when breeding cattle that have had a blood transfusion?

Answer 9

If you breed cattle that have had a blood transfusion, there is an increased risk of neonatal isoerythrolysis

Question 10

How many litres of blood can be donated per donor in cattle?

Answer 10

8 - 10 litres of blood can be donated per donor

Question 11

Give three examples of ectoparasites that can cause anaemia in cattle

Answer 11

Haematobia irritans irritans (horn fly)
Rhipicephalus microplus (major cattle tick)
Haemaphysalis longicornis

Haematobia irritans irrtians

Question 12

Which ectoparasite can cause severe anaemia in calves?

Answer 12

Fleas can cause severe anaemia in calves

Question 13

Which haemoparasites can be carried by ixodes ricinus ticks?

Answer 13

Babesia
Anaplasma

Question 14

Which haemoparasites can be carried by dermacentor reticulatus ticks?

Answer 14

Babesia
Anaplasma

Question 15

How do you diagnose haemoparasites?

Answer 15

You can diagnose haemoparasites using giesma stained blood smears

Question 16

What kind of blood sample should you take if you suspect babesia?

Answer 16

Take a capillary blood sample at the end of the tail as erythrocytes infected with babesia express surface antigens which adhere the cells to capillary endothelium where they will accumulate

Question 17

What can be used to treat babesia?

Answer 17

Imidocarb dipropionate

Question 18

Which disease is caused by anaplasma?

Answer 18

Louping ill

Question 19

Which toxin can cause anaemia in cattle?

Answer 19

Bracken

Question 20

What is the most common form of bracken toxicity?

Answer 20

Enzootic haematuria

Question 21

What is the pathogenesis for enzootic haematura?

Answer 21

Prolonged exposure and ingestion of bracken results in bladder or gastrointestinal wall thickening, metaplasia and the formation of bladder or gastrointestinal carcinomas which bleed into the lumen causing haematuria and anaemia

Question 22

(T/F) In the UK, enzootic haematuria more commonly causes bladder carcinomas

Answer 22

FALSE. In the UK, enzootic haematura more commonly causes gastrointestinal carcinomas

Question 23

What is the signalement for enzootic haematuria?

Answer 23

Enzootic haematuria is typically seen in older cattle as this disease requires prolonged exposures and ingestion of bracken before the disease develops

Question 24

What are the three characteristic clinical signs of enzootic haematuria?

Answer 24

Intermittent haematuria
Anaemia
Gradual loss of body condition

Question 25

What is the signalement for acute bracken toxicity?

Answer 25

Younger cattle that have taken a liking to and have ingested large quantities of bracken

Question 26

Describe the pathogenesis of acute bracken toxicity

Answer 26

When animals ingest high quantities of bracken, the bracken has a radiomimetic affect on the bone marrow which causes thrombocytopenia, leukopenia and anaemia (pancytopenia) resulting in a range of clinical signs and secondary infections

Note the ecchymoses on the mesentery

Question 27

What are the clinical signs of acute bracken toxicity?

Answer 27

Anaemia
Pyrexia
Inappetence
Ecchymoses
Petechiae
Haematuria
Haematochezia
Fibrinous broncho-pnuemonia

Question 28

What can you use to manage acute bracken toxicity?

Answer 28

Activated charcoal
Blood transfusion

However often treatment is unsuccessful