Von Willebrand Disease
Von Willebrand Disease (vWD) is an inherited bleeding disorder that makes it difficult for blood to clot. It is the most common inherited bleeding disorder in dogs, and it can be seen more frequently in certain breeds, such as Doberman Pinschers.
Dogs with vWD may show signs of bleeding, such as skin bruising, bleeding from the gums or nose, and excessive bleeding during surgery. While there is no cure for vWD, dogs can have a normal lifespan with proper care.
A protein called the von Willebrand Factor (vWF) plays an important role in clot formation. For dogs with vWD, this protein can be reduced, dysfunctional or absent all together. This results in prolonged bleeding, because it takes longer for dogs with vWD to form clots.
There are three types of vWD, each defined by either a lack of vWF or poorly functioning vWF. Type I is the most common, particularly in Dobermans, and it is characterized by a partial deficiency in vWF, which causes a mild-to-moderate bleeding risk.
Although less common and more breed-specific, Types II and III are associated with more serious bleeding risks. Dogs with Type II vWD have a low concentration of vWF, as well as an abnormal structure, whereas dogs with Type III may have a complete absence of vWF.
Some of the breeds predisposed to vWD include, but are not limited, to the following:
Type I: Doberman Pinschers, Pembroke Welsh Corgis, Poodles, Bernese Mountain Dogs, Irish Setters, West Highland White Terriers
Type II: German Wirehaired and Shorthaired Pointers
Type III: Scottish Terriers, Kooikerhondje, Shetland Sheepdogs, Chesapeake Bay Retrievers
The clinical signs may vary depending on the amount of functional vWF present. Some dogs may have no obvious signs.
The most common signs include:
Skin bleeding, even from minor wounds
Bleeding from gums (e.g. while teething or chewing on toys)
Bleeding from nose, bladder (blood-tinged urine), vagina, or GI tract (blood in vomit or stools, or dark, tarry stools)
Excessive bleeding after surgery (e.g. spay/neuter, tail docking or ear cropping)
Your veterinarian may perform bloodwork to rule out other forms of bleeding disorders, followed by a simple test that times how quickly a blood clot forms (the buccal mucosal bleeding time, or BMBT). If this test shows delayed clot formation, and the rest of the testing comes back normal, then your veterinarian will want to perform another blood test for the definitive diagnosis of vWD — to check the amount of vWF present in the bloodstream.
There are some IV medications or blood products that can be given before necessary surgical procedures or to control other types of bleeding. Examples include desmopressin acetate (not used in Type III vWD), cryoprecipitate or fresh frozen plasma.
These treatments work by temporarily increasing the amount of vWF in the blood. Your veterinarian may need to avoid certain medications (such as non-steroidal anti-inflammatory drugs, or NSAIDs) that can interfere with normal platelet functions and create additional bleeding risks for dogs with vWD.
There is no cure for vWD. The prognosis will depend on the type of vWD, which correlates to the dog’s risk of bleeding.
With proper management, many dogs with vWD can have a normal lifespan. Strategies can include avoiding cosmetic surgeries, giving proper medications prior to necessary surgeries and avoiding certain medications that can further affect platelet or clotting function.
Because vWD is inherited, dogs suspected of having (or carrying) vWD should not be used for breeding without genetic testing and careful consideration of mate selection. DNA screening is available for several dog breeds.
If genetic testing determines that a dog at-risk for vWD (e.g. carrying two copies of the variant), they may be subsequently tested for the amount of vWF present in their bloodstream to better characterize the severity at that point in time. If a dog is a carrier for vWD (with only one copy of the variant present), your veterinarian may also recommend testing vWF levels, especially if there are concerns that another clotting disorder may be present.
VWD can be caused by several different genetic variants in the vWF gene. Type I vWD, which is the most common, is found in many breeds, and it has one known variant in the vWF gene. This variant is recessively inherited, which means that a dog is at-risk of developing vWD if they have two copies of the variant. However, it is possible for dogs that are carriers of vWD Type I (only one copy of the variant) to have reduced vWF levels.
While not all causative variants for every predisposed breed are known, genetic testing is available for different variants in many breeds predisposed to specific types of vWD. Genetic testing may identify at-risk individuals, and it should be followed by blood tests that measure the amount of vWF to assess bleeding risk.
Learn more about vWD from our Animal Health Diagnostic Center.
This health topic was developed as part of a collaboration between the Cornell Richard P. Riney Canine Health Center and Embark Veterinary, Inc. You can learn more about the hereditary risks of other canine health conditions by exploring our genetics articles.