von Willebrand's Disease, type 3 (Discovered in the Scottish Terrier)

Type 3 von Willebrand’s disease is a moderate to severe clotting disorder. Typical clinical signs include mucosal bleeding, such as nose bleeding, bleeding from the gums, gastrointestinal bleeding, and blood in the urine. Exceptionally excessive and prolonged bleeding may be observed after a trauma or surgery, and spontaneous bleeding may also be encountered. This condition can lead to death if untreated. Most affected dogs will have a normal PT/aPTT but have prolonged bleeding. When assayed, these dogs have no appreciable levels of vWF present; specific vWF factor can be assayed at a reference laboratory. Performing a functional test like a buccal-mucosal bleeding time prior to surgery is recommended.

Some dogs may respond to desmopressin acetate (DDAVP) therapy. In most cases, therapy is limited to supportive care (which can include transfusions if needed) and avoiding surgery. Performing a functional test like a buccal-mucusal bleeding time prior to surgery is recommended.

There are many responsibilities to consider when breeding dogs. Regardless of test results it is important that your dog is in good general health and that you are in a position to care for the puppies if new responsible owners are not found. For first time or novice breeders, advice can be found at most kennel club websites.

This disease is autosomal recessive meaning that two copies of the mutation are needed for disease signs to develop. A carrier dog with one copy of the vWD type 3 mutation can be safely bred with a clear dog with no copies of the vWD type 3 mutation. About half of the puppies will have one copy (carriers) and half will have no copies of the vWD type 3 mutation. Puppies in a litter which is expected to contain carriers should be tested prior to breeding. Carrier to carrier matings are not advised as the resulting litter may contain affected puppies. Use of affected individual for breeding purposes are not recommended for this condition. Please note: It is possible that disease signs similar to the ones caused by the vWD type 3 mutation could develop due to a different genetic or clinical cause.