von Willebrand Disease (Type 1)
Von Willebrand disease (vWD) is the most common inherited bleeding disorder of both humans and dogs. It is caused by a deficiency in the amount of a specific protein needed to help platelets (the blood cells used in clotting) stick together and form clots to seal broken blood vessels. The deficient protein is called von Willebrand factor (vWF).
Clinical signs of vWD range from a mild to severe bleeding tendency. Dogs may “carry” the vWD trait without expressing a bleeding tendency. Severe vWD causes spontaneous bleeding from the nose, mouth, and urinary, reproductive or intestinal tracts. Uncontrollable bleeding may occur after surgery. Dewclaw removal and teething may cause excessive bleeding in vWD-affected pups. Infections, endocrine disorders, and certain medications may exacerbate signs of bleeding in vWD-affected dogs.
Treatment of a severe bleeding episode requires transfusion of canine blood products. There is no drug, vitamin, hormone, or dietary modification that can induce production of vWF. Bleeding from minor injuries may be controlled using sutures, bandages or wound glue. Affected dogs should not be given drugs that interfere with normal blood clotting mechanisms. These drugs include aspirin, sulfa-type antibiotics, and heparin.
Known Mode of Inheritance:
Inheritance and expression patterns of vWD differ between breeds. All males and females have 2 vWF genes, one inherited from dam and one from sire. In many breeds, the presence of 1 abnormal vWF gene appears sufficient to cause abnormal bleeding in some (but not all) dogs. Dogs having 2 abnormal genes express the most severe forms of vWD.
Age of onset: Varies
- Cardigan: yes
- Pembroke: yes
- Other Breeds: yes
Incidence in Cardigans: Unknown (appears sporadic)
- Cardigans: no
- Other breeds: no
- Active?: no
Tests Available: Blood testing is available through veterinarians. Some testing companies will test via cheek swabs.
Published papers and Articles:
- Scottish Terrier Club: Management of Canine von Willebrand’s Disease