Diagnosis and Tests
Von Willebrand disease can be diagnosed through blood tests and bleeding time assessments. Bleeding time tests involve making a tiny incision in the dog’s gum and measuring the amount of time it takes for bleeding from the wound to stop on its own. This normally occurs within 2 to 4 minutes. Nails that are clipped too short typically stop bleeding within 2 to 6 minutes. Blood tests for vWD are also available and involve measuring the levels of von Willebrand factor in circulation. The Orthopedic Foundation for Animals (OFA) maintains a registry for many of the breeds that commonly are diagnosed with vWD. There also is a fairly recent genetic test that can identify both clinically affected and carrier dogs, based upon their DNA. This is the most accurate diagnostic test for von Willebrand disease that is currently available.
Some breeds of dogs seem to be more prone to von Willebrand disease than others. For a few of these breeds, genetic vWD testing is available. While blood tests can predict whether a dog has a clotting disorder, genetic testing is much more reliable.