Coagulation screen

Coagulation screen

Includes prothrombin time (PT), activated partial thromboplastic time (APTT), Thrombin time (TT) and platelet count.

Species: All species – dogs and cats most commonly tested.  Other species can be tested but accurate reference intervals may not be available, so send a control sample from a normal animal for comparison.

Specimen: Whole blood

Container: Citrate (blue top)

Collection protocol:

Collect blood with a minimum of trauma so coagulation cascade is not triggered, preferably from the jugular so a good flow is ensured. Fill the tube to the level indicated on the blood tube

Special handling/shipping requirements:

Samples should reach the laboratory within 18 hours of collection, but the sooner the better. They should be kept at or below room temperature.

General information about the disease:

A coagulation screen will help to differentiate Vitamin K antagonism, inherited coagulopathies, DIC and other rare causes such as severe hepatic disease where there is decreased clotting factor formation.

General information about when this test is indicated:

Where there is unexplained haemorrhage, access to anticoagulant compounds (e.g. Vit K antagonists), and suspected inherited coagulopathies. Also include an EDTA blood sample for a routine CBC and blood smears as described above.

Reference intervals at Awanui Veterinary have been developed using citrated blood.

If citrated blood is not available, in some circumstances a PT only may be carried out on an EDTA blood sample. Accurate reference intervals are not available but moderate to marked increases may diagnose Vit K antagonism. The other parameters i.e. APTT and TT cannot be carried out on EDTA.