Von Willebrand's Disease Type II
Von Willebrand disease (vWD) is the most common inherited bleeding disorder found in dogs and humans. vWD inhibits the normal blood clotting process, causing prolonged bleeding after an injury. People with this condition often experience excessive bruising, prolonged nosebleeds, and excessive bleeding following any form of trauma, including surgery, or dental work.
The primary function of von Willebrand factor (vWF) a blood glycoprotein, is to bind itself to other proteins. The deficiency or failure of vWF function inhibits the blood coagulation process and causes bleeding. This is most apparent in tissues having high blood flow or narrow vessels.
Von Willebrand's disease type II (vWDII):
There have been three separate types of vWD have been identified in dogs (and people). Of these three types, there are five different genetic mutations causing vWDs in dogs. Genetic tests have been developed to identify all five variants. Von Willebrand's disease type II (vWDII) is transmitted as an autosomal recessive trait. vWDII affected dogs have a normal amount of production of von Willebrand factor but significant functional deficiency of the vWF protein.
Acceptable Sample Types:
Animal Genetics accepts buccal swab, blood, and dewclaw samples for testing. Complimentary sample collection kits are available and can be ordered at Canine Test Now.
This Test Is Relevant For the Following Breeds:
Animal Genetics offers DNA testing for von Willebrand's Disease type II. The genetic test verifies the presence of the vWD mutation and presents results as one of the following:
|vWDII/vWDII||Affected||The dog carries two copies of the mutant gene and is homozygous for the mutation associated with von Willebrand's disease type II. The dog IS affected and will always pass a copy of the mutation to its offspring.|
|n/vWDII||Carrier||Both the normal and mutant copies of the gene detected. Dog is a carrier for the von Willebrand's disease type II mutation. The dog is NOT affected but will pass on a copy of the defective gene to its offspring 50% of the time.|
|n/n||Clear||Dog tested negative for the von Willebrand's Disease type II mutation and will not pass on the defective gene to its offspring.|
Am J Vet Res. 2006 Feb;67(2):242-9.
Development of a collagen-binding activity assay as a screening test for type II von Willebrand disease in dogs.
Sabino EP1, Erb HN, Catalfamo JL.