The von Willebrand disease is a bleeding disorder which prevents a dog’s blood from clotting. There are three types of vWD. Cotons happen to have the least serious of those variations in which the von Willebrand factor is extremely low but not absent. Symptoms are excessive bleeding after injury or surgery or evidence of blood in bodily fluids. Thankfully this disease is genetic so any dog owner can find out their dog’s status.

I doubt most people are even aware that such an illness as von Willebrand disease exists when they purchase a puppy.  Some breeders shrug and suggest that they would have realized the pup had vWD when they removed the dewclaws. The pup would have bled out and in essence, removed itself from the gene pool by dying on the spot. Of course, not all of us remove dewclaws, so there is that. Besides, I’d prefer to know what I’m dealing with beforehand if possible and make breeding decisions based on definitive lab results and not experience an avoidable death of a puppy.

Two Types Of Tests

You can test the blood for von Willebrand factor but that just gives you a snapshot of that particular day. Results can fluctuate from day to day and therefore be confusing.

It is much more effective to run the DNA test to see the genetics. Then it can be determined what can be passed on to a litter of pups. If both parents are determined to be clear of that mutation, then the pups are also normal. Pups do not need to be tested in that case.

How von Willebrand Disease Is Expressed

In very broad stoke terms, there are three variable statuses when a mutant gene is autosomal recessive which, von Willebrand disease is:

• Affected is if a mutated gene is inherited from each parent. This pup would express the disease and have life threatening bleeding tendencies.
• Carrier means one normal and one mutated gene has been inherited. The puppy will be unaffected by the mutated gene.
• Clear means two normal genes has been inherited, one from each of his parents and the pup does not have the disease.

If one parent or both parents are carriers, that means each can pass on either the mutation or a clear gene. The pups would have to be tested to determine what they have inherited from each parent. Unless there are two mutated genes, the puppy can lead a normal life.

Understand, you could breed two phenotypically normal dogs that are carriers and you can produce affected puppies. Definition of phenotypical:

“the observable characteristics of an individual resulting from the interaction of its genotype with the environment.”

If you own a dog and you want to know what his status is, you can have the von Willebrand DNA test done yourself. It is a simple cheek swab, sent to any of a number of genetic testing companies which would tell you what you need to know. One company I am using at the moment is Gensol. At the time of this writing a single DNA test costs $30. When you purchase a test, they will send you a cheek swab with instructions on what to do and how to return the cheek swab for testing.

I test all breeding stock for von Willebrand Disease as it is one of the recommended screenings for the coton breed.