What Does a Prothrombin Time Reveal?
Prothrombin time is a measure of the time it takes for blood plasma to clot. It is used to evaluate the proper functioning of certain coagulation proteins. The test detects deficiencies in the extrinsic and common pathways. Of the 12 clotting proteins involved in clotting, PT tests Factors X, VII, V, II and I. Several of these clotting factors rely on vitamin K for proper function. Normal PT in dogs is less than 22 seconds, but this can vary from laboratory to laboratory. Values greater than 22 seconds indicate a potential bleeding disorder. The most common cause of a prolonged PT is poisoning with an anticoagulant rodenticide. How Is a Prothrombin Time Done? In order to check PT, your veterinarian must first draw a blood sample, which is then placed inside a special glass tube. This sample is often submitted to a laboratory for analysis. Some veterinary clinics, and most veterinary emergency facilities, have the capability to run a PT test in their hospital. Others rely on outside lab
