von Willebrand Diease

What is von Willebrand’s Disease and why am I writing about it? It is the most common inherited bleeding disorder in dogs, identified in more than 50 breeds, as well as in mixed-breed dogs. This disease is caused by a deficiency or dysfunction of von Willebrand factor (vWF), a plasma protein required for normal platelet adhesion.

I first learned of this disease from my breeders, Pam and Michelle Koons. They explained that it was one of the medical tests to complete for Kyra, along with OFA for hips and elbows, especially if I intended to breed her. When the time came to have her tested, I talked with some other breeders and while many used to routinely test for it, I discovered there were few, if any, who really thought it was still necessary to have this done any more. They either hadn’t identified this disease as a problem in their lines, or had reasons to believe the tests were inaccurate. I decided to go ahead with it anyway. The normal range for vWF is 70-180%. Kyra’s test came back as 32%. After I freaked, I calmed myself down and convinced myself that this was inaccurate for some reason and I needed to find out why.

As some of you might remember, I’ve written that I feed my dogs the Volhard Natural Diet. There is a list I subscribe to on the internet that is made up of people who support each other in feeding this natural way. They also know a lot about testing and treating dogs for a variety of conditions. The first place I went to get some answers was the Volhard List. I told them about my concern about Kyra and asked if they had any suggestions. They encouraged me to contact Dr. Jean Dodds from the Hemopet Lab in California. She is probably the most knowledgeable person on the planet about this disease since she has been studying it and testing it for 25 years.

I did contact her and received instructions to give to my vet to then have Kyra retested. This time Ky tested borderline normal at 65%. I can breed her but only to a mate with a higher vWF. I felt better about Ky but felt concern that our White Shepherds may have a potential problem that is being ignored and that we might need to address before we run into some real problems. But, the truth is, I didn’t really know if we had a problem or not. I decided to do a written interview with Dr. Jean Dodds and ask her some of the questions I wanted answers to and that some of you might be asking. The interview follows with me asking the questions. I’ll indicate Dr. Dodd’s answers or the material she referenced by boldface type.

von Willebrand’s Disease

Dr. Dodds, if you recall, in December of 1998 I called you and explained that I was very concerned that my dog, Kyra, showed a von Willebrand’s factor (vWF) of 32%. You explained that if the test is not performed properly a false factor can result. You gave me complete instructions to give to my vet. The test was performed a second time with a result of vWF of 65% which is borderline (equivocal) indicating that the dog may be a carrier of von Willebrand’s disease. You also stated that she may be bred but only to a mate with a higher vWF from 70-180%.

I also learned that the majority of White Shepherd owners have no idea what this disease really is. As Health and Genetics Chair for AWSA and a future breeder, I would appreciate some answers for both myself and the membership. I couldn’t think of anyone else to ask but the person who has been working on this issue for over 25 years.

When I started asking breeder friends of mine about vWF, most stated versions of the following:

Their vet advised them the test was inaccurate so there was not much point in doing it.

If properly performed, the test is NOT unreliable – but a commercial company marketing a DNA marker test for certain breeds (not GSD), has claimed so. Their worth has never been published and current literature no longer claims that blood test is "unreliable" – good thing as it is unprofessional and …….

They stated the disease is not in their lines so again there is no reason to do the test.

The Type I disease is much more common than the other types of vWD and has been recognized in more than 50 breeds to date. Breeds with a high prevalence of the vWD gene include the Doberman Pinscher (80%), Scottish Terrier, Minature Poodle, Pembroke Welsh Corgi, German Shepherd (vWD Gene 15 to 80%), Rottweiler, Standard and Toy Manchester Terrier, Keeshond, and the Standard and Miniature Dachschund.

Although relatively few have severe problems and even fewer die from it, many animals are affected by vWD. Bleeding typically involves mucosal surfaces. The bleeding episodes are worsened by physical, emotional, and physiological stresses as well as by other concomitant diseases. Typical clinical signs include: recurrent gastrointestinal hemorrhage with or without diarrhea; recurrent hematuria; existaxis; bleeding from the gums, vagina, or penis; lameness that mimics eisinophilic panosteitis; stillbirths or neonatal deaths ("fading pups") with evidence of bleeding at necropsy; prolonged bleeding at estrus or after whelping; bruises or hematomas on the surface of the body, limbs, or head; excessive umbilical cord bleeding at birth; and excessive bleeding from toenails cut too short or after tail docking, ear cropping, and dew claw removal. Affected dogs may bleed to death from surgical procedures.

They stated the cost is too high for a test that may be faulty.

The cost of the test through Jean Dodd’s lab is $27.00. $20 for the test and $7 for the incidentals like postage, faxes, phone calls, etc. (Complete instructions to give to your vet can be obtained by writing, calling, faxing or E-mailing Judy Huston or calling Dr. Dodd’s at (949) 252-8455.)

It is advisable to test relatives of any dog with a low vWF to assess prevelance in that family.

In your experience, is vWD something we White Shepherd owners need to be concerned about?

YES

Is there still a valid concern about unreliability of the test.

Not if performed properly.

Is there any way of knowing whether it is a problem for us "without" having all of our dogs tested?

Yes, test a representative sample of the breed and relatives of any dog with a low vWF.

Can two dogs with normal vWF produce puppies with abnormal or borderline vWF?

Not unless there was a new mutation (unlikely) or some acquired problem such as hypothyroid which then lowered the vWF level (does happen in some, but not all cases of thyroid).

Note: Thyroid disease is another disease prevalent in our dogs; now that there is an OFA registry for thyroid, it would probably be a good idea to start testing for this as well as for heart problems – also registered with OFA. "Puppies from the Doberman Pinscher and other breeds studied in depth (Golden Retrievers, Miniature Schnauzers, Rottweilers, German Shepherds, Shetland Sheepdogs, Scottish Terriers, Pembroke Welsh Corgis, Manchester Terriers) having low vWF levels, but not showing excessive bleeding (i.e., vWD carriers), often express a bleeding tendency in mid-life when they become hypothyroid. The development of hypothyroidism apparently exacerbates their original trait and compromises hemostasis…"

Will a dog with borderline vWF (like Ky) mated with a dog with a high vWF produce puppies with normal vWF, borderline vWF, abnormal vWF or a combination of these factors?

In theory, you could get normals and low-normals (borderline) or all normals, but if level is above 50% you shouldn’t – or at least only rarely will get a carrier and no affecteds.

Dr. Dodds also stated: vWF is a real ongoing problem in the German Shepherd Dog – but we don’t know what the prevalence is in the white GSD – except that the white coat and other dillute colors in dogs and albino people does produce a tendency for platelet dysfunction. As vWF works on platelet surfaces, white GSD with low vWF could be at more risk for bleeding tendency.