Bleeding disorders can pose diagnostic challenges, but a logical approach to testing for bleeding disorders can simplify the
process. We'll go through some cases we've encountered and how the laboratory tests have helped determine the cause of the
• 9 year old neutered male Labrador
• Presented for epistaxis and hemoptysis
• 5 month old female Great Pyrenees
• Presented for anorexia, lethargy, gingival bleeing and epistaxis
• 9 year old Jack Russell Terrier
• Presented for 3 days history of wheezing, coughing and decreased eating and drinking.
• 10 year old neutered male Welsh corgi
• Presented with dyspnea, lethargy, anorexia
• 9 year old spayed female Doberman Pinscher
• Presented with epistaxis for 1 day. Had been given one aspirin that morning.
• 4 year old spayed female Great Dane
• Presented with bleeding gums, hyphema in left eye
• 9 year old spayed female golden retriever
• Presented for lethargy, anorexia and a mass at the elbow.
Approach to diagnosis of a bleeding disorder
A pertinent history should include
• Frequency, duration, severity of progression
• Age at onset, breed, inherited/acquired
• Type of hemorrhage and location
• Environmental factors
• Drug therapy
• Presence of underlying disease that could compromise hemostasis
• Type and sites of bleeding should be considered carefully
• Small, focal hemorrhage (petechiae) in the skin and mucous membranes suggest vessel wall defect, platelet defects or
von Willebrand disease. Ecchymosis can be observed in both platelet and coagulation defects.
• Deep hemorrhages in body cavities or muscle (hematoma) suggests coagulation factor deficiency.
• Massive bleeding from a single site without a history of a previous bleeding episode or purpura is more suggestive
of a surgical or anatomic defect rather than a coagulation disorder.
Laboratory evaluation of a bleeding disorder
Sodium citrate (light blue top tube) is the anticoagulant of choice for PT and PTT
• Use 9 parts whole blood: 1 part sodium citrate. Tubes must be filled to the fill line or results will be artifactually
• Samples should be kept refrigerated and centrifuged within 60 minutes, plasma collected and tested within 2 hours or
• EDTA is the anticoagulant of choice for platelet counts.