Von Willebrand disease (vWD) is the most common inherited bleeding disorder in dogs, caused by a deficiency or defect in a protein called von Willebrand factor that helps blood clot properly. It has been identified in at least 54 breeds, though some are far more susceptible than others. Dogs with vWD may bleed excessively from minor injuries, during surgery, or sometimes spontaneously from the gums, nose, or urinary tract.
How Von Willebrand Factor Works
Von Willebrand factor (vWF) is a large, sticky protein that circulates in the blood. When a blood vessel is injured, vWF acts like molecular glue: it binds to the damaged vessel wall and then grabs passing platelets, anchoring them to the injury site so a clot can form. Without enough functional vWF, platelets can’t stick where they’re needed, and bleeding continues longer than it should.
vWF also serves as a carrier for another clotting protein called Factor VIII, protecting it from being broken down too quickly. When vWF levels are low, Factor VIII activity drops as well, compounding the clotting problem.
The Three Types of Canine vWD
Not all cases look the same. Canine vWD is classified into three types based on how much vWF the dog produces and whether the protein works normally.
Type 1 is by far the most common form, accounting for over 95% of all cases. Dogs with Type 1 produce vWF that works normally but in reduced amounts. Clinical severity varies widely. Some dogs bleed only after surgery or trauma, while others show signs during everyday life. Breeds commonly affected include Doberman Pinschers, Dachshunds, German Shepherds, Golden Retrievers, Shetland Sheepdogs, Pembroke Welsh Corgis, Poodles, and many others.
Type 2 is rare. Dogs produce low amounts of vWF, and the protein itself is structurally abnormal, meaning it doesn’t function properly even at the levels present. This form causes severe bleeding and is seen primarily in German Shorthaired Pointers and German Wirehaired Pointers.
Type 3 is the most severe form. Dogs produce little to no vWF at all, leading to serious, sometimes life-threatening bleeding episodes. Breeds with a familial pattern of Type 3 include Chesapeake Bay Retrievers, Dutch Kooikers, Scottish Terriers, and Shetland Sheepdogs. Sporadic cases have been reported in Border Collies, Labrador Retrievers, Bull Terriers, Cocker Spaniels, Pomeranians, and mixed breeds.
Breeds at Highest Risk
Doberman Pinschers deserve special mention. Studies have found the prevalence of Type 1 vWD in Dobermans to be staggeringly high: roughly 73% in the United States, around 50% in the United Kingdom, and about 30% in Brazil. If you own a Doberman that hasn’t been tested, the odds are significant that your dog carries the mutation.
The disease was first described in dogs in 1970, in a family of German Shepherd Dogs showing bleeding symptoms similar to the human form of the condition. Since then, it has been documented across dozens of breeds, making breed-specific genetic testing an important tool for breeders and owners alike.
How vWD Is Inherited
Type 1 vWD follows an autosomal dominant inheritance pattern with incomplete penetrance. In practical terms, this means a dog only needs to inherit one copy of the mutated gene (from one parent) to be affected. However, “incomplete penetrance” means not every dog carrying the mutation will actually show clinical signs of bleeding. Some carriers live their entire lives without obvious problems, while others bleed readily. This unpredictability makes genetic testing especially valuable, since a dog that appears healthy can still pass the trait to its offspring.
Type 3, by contrast, is autosomal recessive, meaning a dog needs two copies of the defective gene to be severely affected. Dogs with one copy are carriers who typically don’t show symptoms but can produce affected puppies if bred with another carrier.
Signs and Symptoms
The hallmark of vWD is prolonged or excessive bleeding, particularly from mucosal surfaces. Common signs include nosebleeds, bleeding from the gums, blood in the urine, and bleeding from the genital tract (especially noticeable in females during heat cycles). Many owners first discover the problem after a toenail is trimmed too short and the bleeding won’t stop, or after a routine spay or neuter leads to unexpected hemorrhage.
Some dogs also develop lameness from bleeding into joints, though this is less common than surface bleeding. The severity depends on the type of vWD and how much functional vWF the dog produces. A dog with mild Type 1 may never have a noticeable episode unless it undergoes surgery or significant trauma. A dog with Type 3 can have spontaneous bleeding that requires emergency treatment.
How Veterinarians Diagnose vWD
The primary screening test measures the concentration of von Willebrand factor antigen (vWF:Ag) in the dog’s blood, reported as a percentage of normal. Dogs with levels below 50% are considered at risk of transmitting or expressing the disease. Those with levels below 25% are the most severely affected and most likely to show clinical bleeding.
A complementary in-clinic test is the buccal mucosal bleeding time (BMBT). A small, standardized cut is made on the inside of the dog’s upper lip, and the vet measures how long it takes for bleeding to stop. Normal dogs stop bleeding within about three and a half minutes. A bleeding time longer than that suggests a problem with primary clot formation, which can point toward vWD (though low platelet counts can produce the same result).
DNA testing is now available for the specific mutations behind Types 1, 2, and 3 in predisposed breeds. A simple cheek swab sent to a veterinary genetics lab can confirm whether a dog carries zero, one, or two copies of the relevant mutation. This is the most definitive way to identify carriers before breeding and is routinely recommended for high-risk breeds like Dobermans, Scottish Terriers, and Chesapeake Bay Retrievers.
Treatment During Bleeding Episodes
When a dog with vWD is actively bleeding, the goal is to replace the missing clotting factor. Two blood products are used: fresh frozen plasma and cryoprecipitate. Cryoprecipitate is the preferred option. In a study comparing the two, cryoprecipitate raised vWF levels more effectively than fresh frozen plasma, even though it delivered a smaller total amount of the protein. Equally important, none of the dogs treated with cryoprecipitate experienced adverse reactions, while six out of nine dogs given fresh frozen plasma had side effects ranging from itching to pallor and weakness.
For less severe bleeding, direct pressure, wound care, and avoiding further trauma may be enough. Some mild episodes resolve on their own once the body’s remaining clotting mechanisms catch up.
Managing vWD Before Surgery
If your dog has known or suspected vWD and needs a surgical procedure, your vet will likely take steps beforehand to minimize bleeding risk. One common approach is administering desmopressin (DDAVP), a synthetic hormone given intravenously about an hour before surgery. At a standard dose, desmopressin triggers a temporary release of stored vWF into the bloodstream, significantly boosting clotting ability for a short window. In studies, a single dose produced a meaningful rise in both vWF levels and associated clotting activity within 60 minutes.
Desmopressin works best for Type 1 dogs, who still produce some vWF that can be mobilized. It has limited value in Type 3 dogs, who have virtually no vWF stores to release. For those dogs, cryoprecipitate transfusion before and during surgery is the standard approach.
Living With a vWD-Positive Dog
Most dogs with mild to moderate vWD live normal, happy lives with a few practical adjustments. Keep your vet informed of the diagnosis so they can plan ahead for any procedures, including dental cleanings. Avoid medications that interfere with platelet function, such as aspirin and certain anti-inflammatory drugs, unless specifically directed by your vet. Use caution with nail trims, and keep styptic powder on hand.
For dogs with severe forms, it helps to minimize rough play and situations where injuries are likely. Make sure any emergency vet clinic you might visit has access to your dog’s records and knows about the diagnosis, since uncontrolled bleeding in a Type 3 dog is a genuine emergency. Wearing a medical alert tag on the collar is a simple precaution that could matter in an urgent situation.