Frequently asked questions for the QuickVet® COAG PT/aPTT™ test

What are bleeding disorders?

Bleeding disorders are abnormalities in the hemostasis process (i.e., the formation of a blood clot). Bleeding disorders are split into primary bleeding disorders involve platelet disorders, including thrombopathies and thrombocytopenia as well as von Willebrand’s disease and vasculopathies. Secondary bleeding disorders on the other hand are due to diseases involving coagulation factors. Bleeding disorders can be either acquired or inherited and it is important to point out that bleeding disorders can occur in any animal at any time.

What is hemostasis?

Hemostasis is the process of balancing the need to maintain blood in its natural state while stopping bleeding in cases of trauma or disease. It’s the balance between the formation of blood clots to stop bleeding from injured blood vessels and the prevention of clot formation beyond the site of vessel injury. Too little hemostasis results in hemorrhage while too much hemostasis results in thrombosis for the patient.

Normal hemostasis provides rapid clotting at the site of injury resulting in healing of the injured blood vessel and is divided into:

Primary hemostasis, which results in the formation of a temporary platelet plug.
Secondary hemostasis, which results in the formation of a stable fibrin plug.

Involved in the hemostasis are also anticoagulant and fibrinolytic components that limit the extent of clot (or thrombus) formation and facilitate its breakdown when it have served its purpose.

What is the coagulation cascade?

The Coagulation cascade describes how the different Coagulation factors interact with each other in the formation of a clot. Click here for an overview of the coagulation cascade (PDF). Coagulation factors are proteins that primarily are produced by the liver. They  circulate in the plasma, alongside with platelets, in an inactive form when not required. When activated, coagulation factors through the coagulation cascade interact to form a stable fibrin clot resulting in coagulation. The coagulation cascade is in coagulation theory divided into an intrinsic pathway and an extrinsic pathway, both of which merge into a common pathway that leads to the formation of a clot. All three of these pathways are important in understanding normal clotting mechanisms. The QuickVet® COAG PT/aPTT™ test helps identify deficiencies in these pathways and can help indicate if a permanent fibrin clot will form to stop bleeding. 

Why is in-clinic coagulation testing valuable?

In most key situations where you require coagulation testing sending out for the answer if often not practical or possible due to the timeline required to deal with a critical situation.
Potential rat poison cases requires an immediate answer
Sending out as part of a pre-operation profile in not practical
In-clinic coagulation testing gives you the information when you need it and where you need it

How are bleeding disorders diagnosed?

There are several different tests involved in diagnosing a bleeding disorder completely. These tests should all be interpreted together with a patient’s history, physical exam and clinical findings.

Tests for primary bleeding disorders include:

  • Von Willebrand’s Factor
  • CBC (platelet assessment) and blood film
  • Fibrinogen level

Tests for secondary bleeding disorders include:

  • PT (Prothrombin Time)
  • aPTT (Activated Partial Thromboplastin Time)
  • TT (Thrombin Time)
  • ACT (Activated Clotting Time) 

Does the method of blood sample collection matter?

Proper technique for blood collection is essential for accurate results. Blood should be drawn as atraumatically as possible in a syringe or a blue-top (sodium citrate) tube. Samples with visible clotting or debris should be discarded and a fresh sample obtained. The citrated blood should be analyzed within 2 hours using the citrated whole blood PT/aPTT cartridges. 

When would clinics use the COAG PT/aPTT test?

The QuickVet® COAG PT/aPTT™ test can immediately provide important information regarding the blood clotting status of a patient, when and where veterinarians need it.

Clinics use the test for:

  • Pre-surgical or procedure workup (e.g., liver biopsies) for at-risk animals
  • Clinical signs of excessive bleeding
  • Rat poisoning and other toxins
  • Severe systemic disease (e.g., neoplasia)
  • Disseminated Intravascular Coagulopathy (DIC)
  • Monitoring therapy and disease progression 

Does the QuickVet® COAG PT/aPTT™ test have normal reference intervals?

Yes, the test package insert provides normal reference values for both canine and feline patients. These reference ranges were evaluated by clinical trials for this analyzer and is displayed on the screen together with the result and on printouts .

What animals can be tested with the QuickVet® COAG PT/aPTT™ test?

While the QuickVet® COAG PT/aPTT™ test will work with most species, it has only been validated for Canine and Feline.