Health
What is von Willebrand's disease in dogs?
An inherited deficiency of a blood clotting protein that can cause excessive bleeding from injury or surgery.
← Back to breed profile
Saint Bernard Von Willebrand's Disease: Understanding a Hidden Clotting Problem
Quick answer
What is von Willebrand's disease in dogs?
An inherited deficiency of a blood clotting protein that can cause excessive bleeding from injury or surgery.
A dog with this condition can look and act completely healthy for its entire life until a specific moment, surgery, a deep cut, or trauma, exposes the underlying clotting problem all at once.
This is most relevant to owners scheduling any surgical procedure, including a routine spay or neuter, since knowing a dog's von Willebrand status ahead of time changes how a vet approaches even a straightforward procedure.
Important reminder
This guide is not medical advice. If your dog shows pain, sudden behavior change, or worsening symptoms, consult a licensed veterinarian.
Some links may be affiliate links. We may earn a commission at no extra cost to you. We only suggest products we believe are helpful for dog owners.
Check this first
When bleeding symptoms need urgent attention
Excessive, hard-to-stop bleeding from any wound, prolonged bleeding after a nail trim, blood in the urine or stool, or unusual bruising should prompt an urgent vet visit, since these can indicate a significant clotting problem, whether previously diagnosed or not, that needs specific management.
A known von Willebrand's diagnosis without any active bleeding is not itself an emergency; it's a standing piece of medical information that should be shared proactively with any vet performing surgery or an invasive procedure, so appropriate precautions, like having compatible blood products available, can be arranged in advance.
The most useful practical framing for owners is that this condition is largely about preparation rather than day-to-day monitoring: a dog with known von Willebrand's disease that never needs surgery or sustains a major injury may never have a clinical bleeding event at all, but the same dog undergoing an unplanned emergency procedure without that information on record faces meaningfully higher risk.
If any of these apply, call your vet or an emergency clinic now. The rest of this page is for the cases that are not an emergency.
What this problem looks like
Von Willebrand's disease is an inherited deficiency or dysfunction of a protein essential to normal blood clotting, and it's notable for how invisible it typically is in daily life. A Saint Bernard can carry this condition and show no signs at all until a surgery, deep wound, or significant trauma reveals a clotting problem that had been present, unnoticed, all along, which is exactly why proactive testing matters more than watching for symptoms.
Common triggers
- Inherited genetic deficiency of von Willebrand factor
- Surgical procedures exposing the underlying clotting problem
- Significant trauma or deep wounds triggering excessive bleeding
- Certain medications affecting clotting further in an already deficient dog
- Undiagnosed status simply because no major bleeding event has yet occurred
Von Willebrand's disease is a well-documented inherited condition across a range of breeds, and while it's not universally present in all Saint Bernard lines, its potential presence is significant enough that pre-surgical screening is a reasonable precaution.
Why this happens
Breed factors
Von Willebrand's disease results from an inherited gene mutation affecting production or function of von Willebrand factor, and the condition's prevalence varies by specific bloodline rather than applying uniformly across an entire breed, meaning individual testing is far more informative than assuming risk based on breed alone.
Environment factors
This is a purely genetic condition with no environmental cause, but environmental and situational factors, specifically surgery, trauma, or certain medications, are what actually trigger a clinically significant bleeding episode in a dog that carries the underlying genetic deficiency.
What you can do at home (once it is not an emergency)
When to talk to your vet
Talk to your vet about screening before any surgical procedure, and about any unusual or prolonged bleeding from an injury or nail trim. Excessive, hard-to-stop bleeding, blood in urine or stool, or unusual bruising need an urgent vet visit.
At home, alongside your vet's plan
- Ask your vet about von Willebrand's factor screening before any planned surgery, especially a first procedure like a spay or neuter.
- If your dog is a known carrier or affected, keep that information documented and share it with every vet involved in future care.
- Avoid giving over-the-counter medications that can affect clotting without checking with your vet first, especially if status is unknown.
- If breeding your dog, pursue genetic testing to inform pairing decisions and avoid producing affected puppies unknowingly.
- Keep a close eye on even minor cuts or nail trims for unusually prolonged bleeding, which can be an early clue prompting testing.
Mistakes that raise risk with an undiagnosed bleeding disorder
Because this condition is often invisible until a bleeding event happens, a few gaps in awareness and planning create real risk.
- Skipping a von Willebrand's screening test before a planned surgery, especially in a breed or bloodline where the condition has been documented.
- Assuming a dog is unaffected simply because it hasn't had a bleeding episode yet, when many affected dogs go their whole lives without an obvious injury or surgery to reveal the problem.
- Not informing every vet involved in a dog's care about a known von Willebrand's diagnosis, including for procedures that might seem minor, like a dental cleaning.
- Breeding a dog with a known or suspected von Willebrand's diagnosis without genetic testing and informed pairing decisions.
- Giving over-the-counter pain medications that can affect clotting, like certain anti-inflammatories, without checking with a vet first in a dog with known or suspected von Willebrand's disease.
More Saint Bernard health & behavior issues
VON Willebrands Disease in other breeds
- Cavalier King Charles Spaniel Von Willebrand's Disease
- Cocker Spaniel Von Willebrand's Disease: Signs & What to Do
- Dachshund Von Willebrand's Disease: Signs & What to Do
- English Bulldog Von Willebrand's Disease: Signs & What to Do
- English Cocker Spaniel Von Willebrand's Disease: Signs
- German Shepherd Von Willebrand's Disease: Signs & What to Do
- Great Dane Von Willebrand's Disease: Signs & What to Do
- Havanese Von Willebrand's Disease: Signs & What to Do
- Jack Russell Terrier Von Willebrand's Disease: Signs
- Labradoodle Von Willebrand's Disease: Signs & What to Do
See all Saint Bernard health problems, which breeds are prone to von willebrands disease, or the full Saint Bernard breed guide for temperament, exercise needs and ownership costs.
What to expect, and how you know it is working
Testing can be done at any age and provides a result within days to a couple of weeks, and because this condition is lifelong, its practical relevance is ongoing, most notably resurfacing before any future surgery or significant medical procedure.
Success means having a known status on record well before it's urgently needed, allowing any future surgery or injury to be managed with appropriate precautions in advance rather than being discovered as a crisis during an unplanned bleeding event.
Peter and Yukon: Testing Before an Unplanned Surgery Became a Crisis
Before Yukon's neuter surgery, Peter's vet recommended a von Willebrand's factor screening as a standard precaution for the breed. The test came back showing a moderate deficiency, information that would have gone unnoticed without the screening, since Yukon had never had any bleeding issues from minor cuts before. With that information in hand, Yukon's surgical team took specific precautions, including having compatible blood products on standby, and the neuter proceeded without any excessive bleeding. Peter now keeps Yukon's test results on file to share with any future vet.
Key takeaway: Yukon had shown zero signs of a clotting problem his entire life, and it was the proactive screening before a routine surgery, not any prior symptom, that caught a real risk before it became a crisis on the operating table.
Frequently asked questions
What is von Willebrand's disease?
It's an inherited deficiency or dysfunction of von Willebrand factor, a protein essential for normal blood clotting, which can cause excessive bleeding from injuries or during surgery in affected dogs.
How is von Willebrand's disease diagnosed?
A specific blood test measuring von Willebrand factor levels can confirm the diagnosis, and genetic testing is available for certain breeds to identify carriers and affected dogs before any bleeding episode occurs.
Does every dog with this condition bleed excessively?
No, severity varies significantly. Some affected dogs have only mildly reduced clotting factor and may never experience a notable bleeding episode, while others have more severe deficiency and higher bleeding risk during surgery or injury.
Can von Willebrand's disease be cured?
No, it's a lifelong genetic condition, but it can be managed by informing vets ahead of any procedure and, in some cases, using specific treatments or blood products around surgery to reduce bleeding risk.
Should a dog with von Willebrand's disease be spayed or neutered?
Yes, typically, but the procedure should be planned with the diagnosis in mind, often including precautions like having compatible blood products on hand and possibly a more conservative surgical approach.
Is von Willebrand's disease common in Saint Bernards?
It's a documented genetic condition across several breeds, and testing is the only reliable way to know an individual dog's status rather than assuming based on breed alone.
How much does testing and managing this condition cost?
The screening or genetic test itself is relatively affordable, though any additional surgical precautions needed for a confirmed affected dog can add a modest cost to procedures that would otherwise be routine.
Quick answers
View more answersHealth
How is it diagnosed?
A specific blood test measuring clotting factor levels, or genetic testing, confirms the diagnosis.
Health
Can affected dogs still have surgery?
Yes, with proper precautions and advance planning informed by the diagnosis.
Training
Should I test before breeding my dog?
Yes, genetic testing helps avoid pairings that could produce affected puppies.
Costs
Is testing for this condition expensive?
No, it's a relatively affordable one-time test compared to most veterinary diagnostics.
Related DogBreedCompass guides
- von Willebrand's disease Type 1 explained – A specific subtype of this condition deserves its own more detailed explanation.
- Saint Bernard pregnancy and breeding risks – Breeding health screening decisions extend beyond just this one condition.
- purebred versus mixed breed health risk – Purebred genetics context helps frame how inherited conditions spread through bloodlines.
- Saint Bernard cost of ownership – Owners often want full veterinary cost planning before any surgical procedure.
- liver shunts in Saint Bernard puppies – Liver shunts are another condition where advance genetic or diagnostic awareness changes surgical planning.
Bring the right questions to the vet
A one-page prep sheet for this condition: the signs, the questions to ask, what to get priced. Unlocks here.
You get: Vet visit prep sheet
No spam. One-click unsubscribe. See our privacy policy.
Preview page 1 before you decide.
Related guides
Comparison
Poodle (Standard) vs Saint Bernard: Size, Cost & Temperament
ComparisonRead guide->
Comparison
Poodle vs Saint Bernard: Size, Shedding, Cost & Temperament
ComparisonRead guide->
Comparison
Chihuahua vs Saint Bernard: Size, Shedding, Cost & Temperament
ComparisonRead guide->
Comparison
Mastiff (English Mastiff) vs Saint Bernard: Full Breed Comparison
ComparisonRead guide->
Comparison
Cocker Spaniel vs Saint Bernard: Size, Cost & Temperament
ComparisonRead guide->
Comparison
Rottweiler vs Saint Bernard: Size, Shedding, Cost & Temperament
ComparisonRead guide->