Von Willebrand disease type 2-2 / vWD II (VWF-related) - Dog

What does this test examine?

This genetic test examines the VWF variant c.1657T>G in dogs. The variant causes Von Willebrand disease type 2-2 / vWD II, also known as vWD, von Willebrand disease, von Willebrand factor deficiency or an inherited bleeding disorder.

What does this disorder mean?

Von Willebrand factor is needed for normal platelet adhesion and helps stabilise factor VIII. When this factor is absent, reduced or dysfunctional, blood clotting becomes less efficient. In Von Willebrand disease type 2-2 / vWD II, this concerns a qualitative abnormality of von Willebrand factor with moderate to severe bleeding risk. This can lead to spontaneous bleeding or prolonged bleeding after minor wounds, teething, dental procedures, surgery, birth or trauma.

Possible signs include nosebleeds, bleeding gums, easy bruising, blood in urine or stool, prolonged bleeding and serious blood loss after procedures. For breed-linked variants, it is important to test the correct VWF variant because different breeds can carry different causal mutations.

Inheritance and result

This trait is inherited as autosomal recessive. A dog with two normal copies is clear for the tested variant. A dog with one copy is a carrier and can pass the variant on. A dog with two copies is genetically affected: this genotype causes Von Willebrand disease type 2-2 / vWD II for the tested variant.

The result labels are TT, TG and GG.

Practical value of this test

This test provides practical clarity for breeding, purchase, sale and preparation for situations where bleeding risk matters. In inherited clotting disorders, early carrier detection is especially valuable because healthy carriers can silently pass on the variant and two carriers can produce affected puppies.

• Distinguishes clear, carrier and genetically affected dogs.
• Supports targeted breeding selection and helps avoid carrier-to-carrier matings.
• Supports family screening within a line or breed.
• Provides useful information before surgery, dental procedures, injury management or reproduction.
• Improves transparency for breeders and buyers when this bleeding disorder is relevant within a line.