PATIENT - Abaxis

A prolonged PT and normal aPTT indicatea defect in the extrinsic pathway, while aprolonged aPTT with a normal PT indicates adefect in the intrinsic pathway. If both tests areprolonged, there may be a combined pathwaydisorder, such as Vitamin K antagonism dueto warfarin toxicity or liver disease, or DIC, orthere may be a common pathway disordersuch as an inherited coagulation factor defectsuch as Factor X or Factor II (Prothrombin).Indications for Clotting TimesThere are many congenital and acquired disease entities that can produce acoagulopathy, either from dysfunctional endothelial cells, decreased plateletnumber, platelet dysfunction or decreased clotting factors (See Table 1).Recommendations to establish baseline clotting times include:• Pre-surgical blood work evaluation:Evaluating clotting times as part of a firsttime pre-surgical (i.e. kitten/puppy) bloodscreen can help identify patients withhereditary disorders such as HemophiliaA or B. Identification of these patientsprior to surgery is a necessity to preventprolonged surgical bleeding. Althoughthese diseases can affect any pure ormixed breed canine or feline, veterinariansshould screen the following breeds closelyfor hereditary coagulation disorders:Hemophilia A: Beagles, AlaskanMalamutes, Boxers, MiniatureSchnauzers, BulldogsHemophilia B: Cairn Terriers,Airedales, Coonhounds, St.Bernards, American CockerSpaniels, French Bulldogs, AlaskanMalamutes, Scottish Terriers,Shetland Sheepdogs, LabradorRetrievers, Bichon Frise,Old English Sheepdogs, BritishShort Haired Cat• Hospitalized and Ill Patients: Syndromesthat increase clotting times can includediseases that affect liver function,ingestion of toxins which affect Vitamin Kmetabolism, and diseases that promoteDisseminated Intravascular Coagulopathy.These entities can present subtly in an illpatient and develop into a severe acute lifethreatening syndrome. Baseline clotting timesare recommended for the following diseaseconditions:Sepsis/Infectious (Parvo Viral Infection,Pneumonia, Pyometra…)Liver DiseaseHeat StrokeAnemia/HemorrhageToxins or PoisoningsSevere Metabolic Disease (DiabeticKetoacidosis (DKA), Amyloidosis…)NeoplasiaPatients requiring surgical procedure orsurgical biopsy should always have athorough coagulation profile completed priorto the procedure.08 April 2010