Lab 1

Question 1

Primary hemostasis tests

Answer 1

• Platelet count
• Platelet estimate
• von Willebrand’s Factor (vWF) assay
• Buccal Mucosal Bleeding Time (BMBT) test

Question 2

Buccal Mucosal Bleeding Time (BMBT) test

Answer 2

• Assesses the ability of an animal to form a platelet plug
• Normally < 4 minutes in dogs, 1to 2.5 minutes in cats
• Increased with thrombocytopenia, platelet dysfunction, vWF deficiency
• Dogs with coagulation factor deficiencies usually have normal BMBT tests

Question 3

Platelet count

Answer 3

• Normal platelet count 150,000-400,000/µL

* Bleeding occurs with platelet counts <40,000/µL

Question 4

Secondary hemostasis tests

Answer 4

• Prothrombin Time (PT)
• activated Partial Thromboplastin Time (aPTT)
• Activated Clotting Time (ACT) test

Question 5

Prothrombin Time (PT)

Answer 5

• Assesses function of extrinsic and common coagulation pathways
• Prolonged PT and aPTT tests indicate depletion of coagulation factors to < 30% of normal levels
• Blood must be collected atraumatically into a vacutainer tube containing sodium citrate

Question 6

activated Partial Thromboplastin Time (aPTT)

Answer 6

• Assesses function of intrinsic and common coagulation pathways
• Prolonged PT and aPTT tests indicate depletion of coagulation factors to < 30% of normal levels
• Blood must be collected atraumatically into a vacutainer tube containing sodium citrate

Question 7

Activated Clotting Time (ACT) test

Answer 7

• Assesses function of the intrinsic and common coagulation pathways
• Not as sensitive as the aPTT test
• Can be done in-house and results are available immeditately

Question 8

Other laboratory tests

Answer 8

• Fibrinogen

* Fibrin Degredation Products (FDP’s)