Type 3 Von Willebrand Disease in Dogs: Understanding the Severe Inherited Bleeding Disorder

Type 3 Von Willebrand Disease (VWD) is a severe inherited bleeding disorder that affects dogs and is caused by a complete absence of von Willebrand factor (vWF), a glycoprotein essential for blood clotting. Dogs with Type 3 VWD have little to no vWF in their bloodstream, leading to life-threatening bleeding tendencies. In this in-depth article, we explore Type 3 Von Willebrand Disease in relation to dogs, shedding light on its significance and the measures necessary to support the affected canine breeds.

Understanding Type 3 Von Willebrand Disease

Von Willebrand factor is crucial for platelet adhesion and blood clot formation. In Type 3 VWD, dogs lack functional vWF, resulting in severely impaired blood clotting ability.

Genetic Basis of Type 3 Von Willebrand Disease

Type 3 VWD is inherited as an autosomal recessive trait, similar to Type 1 and Type 2 VWD. For a dog to express the disorder, it must inherit two copies of the mutated gene, one from each parent. Dogs with one copy of the mutated gene are carriers and do not show symptoms but can pass the gene to their offspring.

Symptoms of Type 3 Von Willebrand Disease

The symptoms of Type 3 VWD in dogs are severe and can lead to life-threatening bleeding events. Common signs include:

  1. Excessive Bleeding: Dogs with Type 3 VWD may experience excessive bleeding from even minor injuries or surgical procedures.
  2. Spontaneous Bleeding: Unprovoked bleeding from the gums, nose, or other mucous membranes may occur.
  3. Internal Bleeding: Dogs may experience internal bleeding, leading to symptoms such as weakness, lethargy, and pale gums.
  4. Joint Bleeding: Bleeding into the joints (hemarthrosis) may cause swelling, lameness, and pain.
  5. Gastrointestinal Bleeding: Dogs may pass blood in their stool or vomit blood in severe cases.

Diagnosing Type 3 Von Willebrand Disease

Diagnosing Type 3 VWD requires specific diagnostic tests to confirm the absence of vWF in the blood. These may include:

  1. Von Willebrand Factor Assay: A laboratory test that measures vWF levels in the blood, with Type 3 VWD showing severely reduced or undetectable levels.
  2. Platelet Function Testing: Assessing platelet function in response to vWF is essential for confirming the diagnosis.
  3. Genetic Testing: Identifying carriers of the mutated gene is crucial for breeding decisions.

Treatment and Management

There is no cure for Type 3 VWD, and treatment primarily focuses on managing bleeding tendencies and improving the dog’s quality of life. Treatment options may include:

  1. Blood Transfusions: In cases of severe bleeding or surgical procedures, blood transfusions may be necessary to replace clotting factors.
  2. Avoidance of Certain Medications: Dogs with Type 3 VWD should avoid medications that can interfere with blood clotting.
  3. Preventive Measures: Preventing injuries and minimizing activities that may lead to bleeding are essential for managing Type 3 VWD.

Breeding Considerations

Responsible breeding practices are critical to reducing the prevalence of Type 3 VWD in susceptible canine breeds. Genetic testing can identify carriers and help prevent the transmission of the mutated gene to offspring.


Type 3 Von Willebrand Disease is a severe inherited bleeding disorder that affects certain canine breeds. Understanding the genetic basis, symptoms, diagnosis, treatment options, and management strategies is essential for dog owners and veterinarians to provide the best care and support for their affected companions. Early detection, responsible breeding practices, and appropriate management can contribute to improving the quality of life for dogs with Type 3 VWD and potentially reduce its occurrence in susceptible breeds. By promoting awareness and taking preventive measures, we can ensure that dogs with Type 3 Von Willebrand Disease lead happy, healthy lives as cherished members of our families.