Old English Sheepdog Von Willebrand's Disease Type 1: What a DNA Test Actually Tells You

The three recognized types of von Willebrand's disease differ in both how severely they reduce clotting protein function and how reliably they can be genetically tested. Type 1 involves a partial quantitative reduction in von Willebrand factor, meaning some functional protein is still present, generally producing a milder clinical picture than Types 2 or 3, where the protein is either structurally abnormal or almost entirely absent. Type 1 also has a well-characterized genetic mutation that a straightforward DNA panel can detect directly, unlike a general clotting time test, which only shows that something is off without specifying the type or exact genetic cause. This is why a specific Type 1 genetic result carries real diagnostic weight, rather than being a vague flag needing further interpretation.

A clear result means a dog carries no copies of the tested Type 1 mutation. A carrier result means one copy is present, generally without clinical symptoms, though the dog can pass the mutation to offspring. An affected result means two copies are present, which is associated with an actual clotting deficiency, though even among affected dogs, severity can range from clinically silent to genuinely significant, which is why an affected genetic result is often paired with an actual clotting function test rather than treated as automatically defining a clinical severity level. For breeding purposes, avoiding carrier-to-carrier or carrier-to-affected pairings is the most direct way to reduce how often affected puppies are produced in future litters.

If you think your Old has von willebrand's disease (vwd1), the plan is three steps: write down what you have seen and when it started, book a veterinary appointment rather than waiting for the next flare, and take video of the behaviour or symptom before you go — the thing you are worried about rarely happens in the consulting room. Screening in the parents covers hip dysplasia, cataracts, hypothyroidism.

What the vet visit should produce is a diagnosis and a written plan, not just reassurance: what is being ruled out, what the monitoring interval is, and which signs mean you come back sooner. Ask what the treatment costs across a year rather than per visit, because that is the number that decides whether you are managing this condition or reacting to it.

Between appointments, keep a short log — dates, what you saw, what changed. It is the single most useful thing an owner brings to a follow-up, and for von willebrand's disease (vwd1) it is often what separates a clear pattern from a guess.