Disorders of Haemostasis

Question 1

Define haemostasis

Answer 1

Stopping of the flow of blood

Question 2

3 stages of haemostasis

Answer 2

Primary Haemostasis: Formation of platelet plug
Secondary Haemostasis: Stabilisation of platelet plug (Fibrin formation)
Tertiary Haemostasis: Breakdown of platelet plug

Question 3

What is the function of von williebrand factor

Answer 3

Involved in the tethering platelet to vascular wall involved in primary haemostasis

Question 4

What is the name and function of the protein most involved in tertiary haemostasis

Answer 4

Plasmin. Breaks down crosslinked fibrin to fibrin degradation products

Question 5

List common disorders of primary haemostasis

Answer 5

Thrombocytopenia
Thrombocytopathia (Platelet dysfunction)
Von Willebrand’s disease (Congenital)
Vasculopathies

Question 6

List common disorders of secondary haemostasis

Answer 6

Anticoagulant rodenticide toxicity
Liver failure
Congenital factors e.g. Haemophilia

Question 7

Haemophilia

Answer 7

Congenitial disease that affects clotting

Question 8

What is the most common congenitial bleeding disorder in german shepards

Answer 8

Hemophilia A/Factor VIII Deficiency is an inherited bleeding disorder in German Shepherd Dogs and related breeds caused by a deficiency of the coagulation factor VIII (F8), a protein necessary for blood clotting.

Question 9

What is the most common congenital bleeding disorder in doberman pincher

Answer 9

Von Willebrand Disease (vWD)

Question 10

What are common clinical findings of thrombocytopenia

Answer 10

Petechiation
Ecchymosis
GI bleeding causing melaena
Clinical signs associated with anemia

Question 11

Petechiation

Answer 11

pinpoint, reddish or purplish spot containing blood that appears in skin or mucous membrane as a result of localized hemorrhage

Question 12

Ecchymosis

Answer 12

Broad localised bruises

Question 13

Melaena

Answer 13

Blood in faeces

Question 14

List laboratory assessment for primary haemostasis

Answer 14

Platelet count
BMBT (Buccal mucosal bleeding time)
Activated clotting time

Question 15

What are common clinical findings of Von Willebrand Disease

Answer 15

Excessive bleeding at surgical sites
Prolonged bleeding at oestrous

Question 16

What are common clinical findings of coagulopathies

Answer 16

Haematoma formation
Pulmonary haemorrhage
Bleeding into body cavities

Question 17

List laboratory assessment for secondary haemostasis

Answer 17

Standard coagulation test:
Prothrombin time
Activated partial thromboplastin time
Fibrinogen
Activated clotting time

Question 18

List laboratory assessment for tertiary haemostasis

Answer 18

Fibrin degradation products

Question 19

Causes of thrombocytopenia

Answer 19

Immune mediated thrombocytopenia
Bone marrow failure
Infectious disease (Anaplasmosis/Ehrilichosis)
Increased consumption (Severe blood loss)
Breed variation

Question 20

Cocker spaniels are predisposed to have what haemostatic disorder?

Answer 20

Immune mediated thrombocytopenia

Question 21

How is immune mediated thrombocytopenia diagnosed

Answer 21

Diagnosed by exclusion
Clinical signs include surface/capillary bleeding (Primary haemostatic disorder)
Low platelet count

Question 22

Management of Immune mediated thrombocytopenia

Answer 22

Gentle handling
Blood transfusion if anemic enough
Treatment of underlying trigger if secondary
Immunosupression
Vincristine to increase number of circulating platelets

Question 23

Diagnosis of anticoagulant rodenticide toxicity

Answer 23

History of potential exposure
Lab test for secondary haemostatic disorders
Increased prothrombin time

Question 24

Treatment for anticoagulant rodenticide toxicity

Answer 24

<6 hours: emesis (vomitting), monitoring PT
Vit K1
Supportive care

Question 25

Clinical signs for liver disease

Answer 25

Coagulopathy: Cavity bleeds Increased risk for bleeding with biopsy

Question 26

How does liver disease affect haemostasis

Answer 26

Failute to absorb Vit K1 Reduced production of clotting factors Reduced acitvation of vitamin K dependant factors

Question 27

Which protein clotting time would you look at if confirming a diagnosis for liver disease

Answer 27

Prolonged prothrombin clotting time

Question 28

Name the parasite that can cause haemostasis disorders

Answer 28

Angiostrongylus Vasorum (French Lungworm)

Question 29

Lungworm diagnosis

Answer 29

Faecal Baermann’s test for L1 larvae (3-day pooled sample to increase sensitivity) Faecal wet prep In-house ELISA: IDEXX Angio Detect

Question 30

Treatment for lungworm

Answer 30

Supportive care for haemorrhage (transfusion?) Parasite kill Imidacloprid/ moxidectin and milbemycin licenced in UK Steroids: for ‘worm-kill’ effect

Question 31

What is DIC

Answer 31

Disseminated Intravascular Coagulation Dysfunction of the normal regulatory mechanisms of coagulation and fibrinolysis resulting in unregulated production of THROMBIN and self-perpetuating activation of coagulation and fibrinolysis.

Question 32

Clinical signs of DIC

Answer 32

Mixture of thrombosis and bleeding

Question 33

Treatment of DIC

Answer 33

Eliminating initiating cause Ensuring adequate tissue perfusion Supporting target organs susceptible to microthrombi, ischaemia or haemorrhage Replacement of blood components

Question 34

Thrombocytopathia

Answer 34

Platelet Dysfunction Usually associated with an underlying disease process

Question 35

Diagnosis of Thrombocytopathia

Answer 35

Normal PLT count and standard coagulation tests Prolonged BMBT (Ddx von Willebrand’s Disease)

Question 36

Oral petechiae in a cat could be caused by?

Answer 36

Primary coagulation disorders Thrombocytopenia Concurrent DIC could be a differential

Question 37

PPT (activated thromboplastin time) determines which pathways?

Answer 37

Intrinsic and common pathway

Question 38

PT (prothrombin time) determines which pathways?

Answer 38

Extrinsic and common

Question 39

Prolonged PPT time with normal PT time suggest deficiency in which factors and what disease?

Answer 39

Factor 8 (VWD and haemophilia A) Factor 9 (Haemophilia B) Factor 11/12

Question 40

Prolonged PT time with normal PPT time suggest deficiency in which factors and what disease

Answer 40

Factor 7 (DIC/Vit K antagonism)

Question 41

What does Prolonged PT time and PPT time suggest

Answer 41

Vit K deficiency Rodenticide toxicity Excessive warfarin treatment Liver disease