class notes 9 - flashcards

Flashcards about Coagulopathies and related bleeding disorders, causes, and treatments.

What type of animals are Inherited coagulation defects more common in?

Purebred animals

What is the primary function of vWF that is affected in von Willebrand's disease?

Formation of the primary platelet plug

What is the genetic defect in animals with Haemophilia A?

Deficiency of factor VIII

What test is prolonged in animals affected with von Willebrand's disease?

Bleeding Time test

What test result would you expect to see in an animal with Haemophilia A?

Prolonged APTT with normal PT and TCT

What is the mechanism of action of anticoagulant rodenticides?

Inhibits vitamin K.

What causes death due to anticoagulant rodenticides?

Haemorrhages that result in severe anaemia or hypovolemic shock

What is an antidote for anticoagulant rodenticide poisoning?

Vitamin K1

How do fungi contribute to Sweet clover poisoning?

Metabolize coumarins to dicoumarol

What is the underlying cause of coagulopathy due to Hepatic failure?

Inadequate production of coagulation factors

What is the most common bleeding disorder in dogs and cats?

Thrombocytopaenia

What is the mechanism of Immune mediated thrombocytopaenia (IMTP)?

Development of autoimmunity to platelets or megakaryocytes, with phagocytosis occurring in the spleen

What is Disseminated Intravascular Coagulation (DIC)?

A possible consequence of many serious conditions

Name two general mechanisms that can trigger DIC.

Excessive release of coagulation activating substances & widespread injury to endothelial cells

What characterizes the onset of DIC?

Widespread formation of fibrin thrombi in the microvasculature

What are the laboratory findings associated with DIC?

Elevated FDPs, thrombocytopaenia, hypofibrinogenaemia, and the presence of schistocytes

What causes microangiopathic haemolytic anaemia in DIC?

Deformed erythrocytes

Name three conditions that may result in DIC

Extensive necrosis, shock, vasculitis, sepsis, cancers, burns, systemic viral diseases, heat stroke, snake bite, acute pancreatitis, polycythaemia, nephrotic syndrome

Why can sepsis lead to DIC?

LPS induced expression of tissue factor by endothelium and monocytes & LPS induced activation of factor XII

What component of snake venom can cause platelet lysis?

Phospholipase A

How does polycythaemia contribute to DIC?

Increased viscosity of blood causes sludging or turbulence and permits platelets to contact the endothelium

How does nephrotic syndrome contribute to DIC?

Renal loss of AT-III

What is the genetic defect in animals with Haemophilia B?

Deficiency of factor IX

What are two examples of second-generation anticoagulant rodenticides?

Brodifacoum and bromadiolone

What breed of dog has the highest prevalence of von Willebrand’s Disease?

Doberman Pinschers

What is thought to cause drug-induced thrombocytopaenia?

Idiopathic, hapten formation

What does a prolonged APTT test result indicate?

A deficiency in coagulation factors

Which coagulation factors are vitamin K dependent?

Factors II, VII, IX, and X

What causes thrombocytopenia?

Increased destruction or decreased production of platelets

What is the mechanism of action of Warfarin?

Vitamin K antagonist

What is the function of AT-III?

Antithrombin III, a natural anticoagulant

What is the source of coumarin in Sweet clover poisoning?

Innocuous coumarin chemicals found in sweet clover

How long after poisoning by anticoagulant rodenticides before you will see clinical signs?

2 to 5 days

How can you detect anticoagulant rodenticides?

Toxicological detection can be achieved in fresh samples of liver

What test is most sensitive to anticoagulant rodenticide poisoning?

PT

Is DIC a primary disease?

No

What causes aplastic anemia?

Chloramphenicol toxicosis

What is a clinical sign of DIC?

Widespread petechial haemorrhages

Which factor is affected by hemophilia A?

Factor VIII

What is the difference between coumarin derivatives and inanediones?

They are both examples of anticoagulant rodenticides