Von Willebrand's Disease in Dogs: Health Testing Guide

Von Willebrand's Disease (vWD) is an inherited blood clotting disorder affecting dogs and presents serious health concerns. This condition results from a deficiency or dysfunction of Von Willebrand factor, a key protein necessary for proper blood clotting.

Named after this clotting protein, vWD impairs a dog's ability to form clots effectively, causing prolonged bleeding from even minor cuts or internal injuries. Owners must be cautious to avoid injuries and carefully manage affected dogs.

The disease is hereditary, passed genetically from parents to puppies. In the United States, veterinary organizations like the American Kennel Club (AKC) and veterinary experts recommend that dogs from at-risk breeds undergo testing before breeding to minimize spreading the condition.

Understanding Von Willebrand's Disease in Dogs

There are three primary vWD types in dogs:

• Type 1: The most prevalent and mildest form, marked by a reduced amount of functional Von Willebrand factor. Dogs may show minimal or no signs but can still carry and pass on the gene.
• Type 2: A rarer form involving an abnormal but present clotting factor.
• Type 3: The most severe form where Von Willebrand factor is virtually absent, leading to serious bleeding risks.

Symptoms in puppies often become apparent soon after birth, such as excessive bleeding from the umbilical cord or during teething. Adult dogs may suffer from prolonged bleeding, bloody urine or stool, frequent nosebleeds, or unusual bruising. Since Type 1 can be symptomless, testing your dog is crucial even if no symptoms show.

Breeds Frequently Affected by vWD in the US

More than 50 breeds can carry the gene linked to vWD. Several breeds, however, have higher prevalence in America, including the Doberman Pinscher, Basset Hound, and Dachshund. Additionally, breeds like the German Shepherd, Standard Poodle, and Golden Retriever are commonly screened. The AKC provides breed-specific health testing recommendations.

Unlike hemophilia which typically affects males, vWD can affect both male and female dogs equally in the US.

Genetic Inheritance of vWD

vWD follows an autosomal recessive inheritance pattern:

• If neither parent carries the mutated gene, puppies are unaffected.
• If both parents are affected, all their offspring will have the disease.
• If one parent is a carrier and the other is clear, puppies may be carriers but usually don't develop symptoms.
• If two carriers breed, their puppies can be clear, carriers, or affected depending on genetic combinations.

This means carriers can unknowingly pass vWD along without showing any symptoms, underscoring the importance of testing.

Testing Techniques for Von Willebrand's Disease

Two primary tests are commonly utilized:

1. Blood von Willebrand Factor Assay

This lab test measures the amount of functional von Willebrand factor in the blood. Dogs with levels below 50% are at risk, and severely affected dogs often have less than 25%. Blood assays are typically used when dogs exhibit symptoms or pre-operatively.

2. DNA Testing for Type 1 vWD Mutation

This genetic test detects a specific mutation often responsible for Type 1 vWD in certain breeds. It requires a cheek swab and is less invasive. Dogs are categorized as clear, carriers, or affected. This test is crucial for making responsible breeding choices.

In the US, DNA testing is available for breeds including the Doberman Pinscher, Bernese Mountain Dog, Labradoodle, Poodle, and Welsh Corgi, among others. Mixed-breed dogs with ancestry from these types can also be tested.

The Importance of Testing

Testing is key to identifying carriers and affected animals, enabling breeders and owners to avoid breeding carrier-to-carrier pairs and reduce vWD incidence. For owners, knowing a dog's status supports better management of bleeding risks and health decisions.

Combining blood factor assays with genetic testing offers the most thorough approach to managing vWD risk, serving both diagnosis and breed health strategies.

Care Tips for Owners

• Monitor dogs with vWD carefully to reduce injury risk.
• Avoid elective surgeries or procedures that might cause bleeding without consulting your veterinarian.
• Always notify your veterinarian of your dog’s vWD status before treatment plans.
• Schedule regular veterinary check-ups and seek prompt care for any bleeding episode.

Being well-informed and proactive testing helps protect your dog and supports healthier breeding practices across the US.

Regional Insight: Dobermen in the Midwest

In the American Midwest, Doberman Pinschers are notably predisposed to vWD. Many veterinary clinics recommend pre-surgical genetic screening for Dobermans in this area to minimize complications during procedures.