Common Symptoms
Von Willebrand disease type II (VWDII) is an inherited bleeding disorder affecting dogs. Dogs affected with VWDII have decreased levels and abnormal function of von Willebrand coagulation factor (vWf), which is an essential protein needed for normal blood clotting. Affected dogs generally have moderate to severe signs of a bleeding disorder. Affected dogs may bruise easily, have frequent nosebleeds, bleed from the mouth when juvenile teeth are lost and experience prolonged bleeding after surgery or trauma. The bleeding may be severe enough to cause death. Due to variable severity of the disorder, affected dogs may not be identified until a surgery is performed or trauma occurs at which time excessive bleeding is noted. Veterinarians performing surgery on known affected dogs should have ready access to blood banked for transfusions. Dogs can have a normal lifespan with this condition although they are susceptible to life-threatening bleeding with an accidental injury or any surgical procedure.
Testing Tips
Genetic testing of the VWF gene will reliably determine whether a dog is a genetic Carrier of von Willebrand disease II. Von Willebrand disease II is inherited in an Autosomal Recessive manner in dogs meaning that they must receive two copies of the mutated gene (one from each parent) to develop the disease. In general, carrier dogs do not have features of the disease but when bred with another carrier of the same Mutation, there is a risk of having affected pups. Each pup that is born to this pairing has a 25% chance of inheriting the disease and a 50% chance of being a carrier of the VWF gene mutation. Reliable genetic testing is important for determining breeding practices. In order to eliminate this mutation from breeding lines and to avoid the potential of producing affected pups, breeding of known carriers to each other is not recommended. Dogs that are not carriers of the mutation have no increased risk of having affected pups.
There may be other causes of this condition in dogs and a normal result does not exclude a different mutation in this gene or any other gene that may result in a similar genetic disease or trait.
References
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van Dongen AM, van Leeuwen M, Slappendel RJ. Canine von Willebrand's disease type 2 in German wirehair pointers in the Netherlands. Vet Rec. 2001 Jan 20; 148(3):80-2.
[PubMed: 12503596]
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Vos-Loohuis M, van Oost BA, Dangel C, Langbein-Detsch I, Leegwater PA. A novel VWF variant associated with type 2 von Willebrand disease in German Wirehaired Pointers and German Shorthaired Pointers. Anim Genet. 2017 Aug;48(4):493-496.
[PubMed: 28696025]
