PATHOLOGY - Bovine Anaemia Flashcards
What are the three most common causes of anaemia in cattle?
Haemorrhage
Infectious agents
Toxicity
What are five common causes of haemorrhage in cattle?
Trauma
Castration
Dehorning
Obstetric haemorrhage
Abomasal ulceration
What are three common traumatic causes of haemorrhage in cattle?
Trauma to the udder
Ruptured middle uterine artery
Epistaxis due to caudal vena caval syndrome
What is the average blood volume for cattle?
55ml/kg blood volume
How can you calculate the allowable blood loss in cattle?
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
What is a normal PCV in cattle?
A normal PCV in cattle is above or equal to 24%
What can you use to manage haemorrhage in cattle?
Intravenous and oral fluid therapy
Blood transfusion
(T/F) You do not need to cross-match before transfusing blood to cattle
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
What should you be aware of when breeding cattle that have had a blood transfusion?
If you breed cattle that have had a blood transfusion, there is an increased risk of neonatal isoerythrolysis
How many litres of blood can be donated per donor in cattle?
8 - 10 litres of blood can be donated per donor
Give three examples of ectoparasites that can cause anaemia in cattle
Haematobia irritans irritans (horn fly)
Rhipicephalus microplus (major cattle tick)
Haemaphysalis longicornis
Which ectoparasite can cause severe anaemia in calves?
Fleas can cause severe anaemia in calves
Which haemoparasites can be carried by ixodes ricinus ticks?
Babesia
Anaplasma
Which haemoparasites can be carried by dermacentor reticulatus ticks?
Babesia
Anaplasma
How do you diagnose haemoparasites?
You can diagnose haemoparasites using giesma stained blood smears
What kind of blood sample should you take if you suspect babesia?
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
What can be used to treat babesia?
Imidocarb dipropionate
Which disease is caused by anaplasma?
Louping ill
Which toxin can cause anaemia in cattle?
Bracken
What is the most common form of bracken toxicity?
Enzootic haematuria
What is the pathogenesis for enzootic haematura?
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
(T/F) In the UK, enzootic haematuria more commonly causes bladder carcinomas
FALSE. In the UK, enzootic haematura more commonly causes gastrointestinal carcinomas
What is the signalement for enzootic haematuria?
Enzootic haematuria is typically seen in older cattle as this disease requires prolonged exposures and ingestion of bracken before the disease develops
What are the three characteristic clinical signs of enzootic haematuria?
Intermittent haematuria
Anaemia
Gradual loss of body condition
What is the signalement for acute bracken toxicity?
Younger cattle that have taken a liking to and have ingested large quantities of bracken
Describe the pathogenesis of acute bracken toxicity
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
What are the clinical signs of acute bracken toxicity?
Anaemia
Pyrexia
Inappetence
Ecchymoses
Petechiae
Haematuria
Haematochezia
Fibrinous broncho-pnuemonia
What can you use to manage acute bracken toxicity?
Activated charcoal
Blood transfusion
However often treatment is unsuccessful