Type 1 von Willebrand’s disease is the mildest form of vWD and while many dogs may be subclinical, some dogs may exhibit more severe clinical signs. Excessive bleeding may be observed after a trauma or surgery. Not all affected pups will exhibit the same severity of clinical signs as these are related to the amount of vWF present, which vary between affected individuals. An affected dog will have a normal PT/aPTT but have prolonged bleeding. When assayed, these dogs usually have low levels of vWF; specific vWF factor can be assayed at a reference laboratory. Performing a functional test like a buccal-mucusal bleeding time prior to surgery is recommended. Some carriers may show clinical signs though dogs with two copies of the mutation tend to be more severely affected. Medications known to interfere with clotting should be avoided. Some dogs may exhibit some improvement when treated with desmopressin acetate.

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 occur. However, carriers of one copy can show clinical signs. A carrier dog with one copy of the vWD type 1 mutation that does not show clinical signs can be safely bred with a clear dog with no copies of the vWD type 1 mutation. About half of the puppies will have one copy (carriers) and half will have no copies of the vWD type 1 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. Please note: It is possible that disease signs similar to the ones caused by the vWD type 1 mutation could develop due to a different genetic or clinical cause.