Issue Description Von Willebrand's Disease is a genetic bleeding
disorder. Dogs affected with vWD will have a reduction in the amount
or function of a blood protein which binds platelets to blood vessels.
This blood protein is commonly referred to as Von Willebrand's Factor
(vWF). The factor can come from plasma, endothelial cells, or the
subendothelium. The absence or deficiency of the factor can be life
threatening by leading to uncontrolled bleeding episodes. It is a
complex and difficult disorder to deal with, because genetics,
diagnostic abnormalities, and sometimes-conflicting clinical signs are
all involved. Other Names vWD
Breeds At Risk
Type I vWD is characterized by a low
concentration of normally structured protein. In screening studies
done at Cornell over a period of years (1982-1992), percentages of
dogs of some breeds tested as carrying the disease, and with
concentrations of vWF less than 50% of standard (considered to be at
risk) were: Corgi, Poodle (std & min), Scottie, Golden Retriever,
Doberman, Sheltie, Akita, Cairn Terrier. Other breeds with a known
prevalence of vWD in excess of 15% include Basset Hounds, Dachshunds
(mini & std), German Wirehaired Pointers, German Shepherds, Keeshonds,
Manchester Terriers (std & toy), Miniature Schnauzers, and
Type II vWD is characterized by a low concentration of an abnormal
vWF. Breeds in which severe type II-like vWD has been diagnosed
include American Cocker Spaniels, German Shorthaired Pointers, and
German Wirehaired Pointers.
Type III vWD is essentially the complete absence of vWF. Severe
type III vWD has been diagnosed in Australian Cattle Dogs, Chesapeake
Bay Retrievers, Fox Terriers (toy), German Shepherds, Scottish
Terriers, and Shetland Sheepdogs.
Symptoms The clinical signs of vWD are typical of a
platelet function defect, such as spontaneous hemorrhage for mucosal
surfaces, epistaxis, hematuria, melena and excessive hemorrhage from
surgery or trauma. Stillbirths, neonatal deaths, prolonged bleeding at
tail docking, ear cropping or dewclaw removals are other common
manifestations. Bleeding from gums, excessive umbilical cord bleeding
at birth, excessive bleeding from toenails cut too short, and bleeding
after elective procedures. Some other clinical signs are: bloody
stools, feces, hematochezia , forelimb lameness, forelimb swelling,
generalized lameness or stiffness, head, face, ears, jaw, nose, nasal,
swelling, hematuria, hemorrhage of any body part or clotting failure,
hind limb lameness, hind limb swelling, hyphema, neck swelling, pale,
pelvic or perennial swelling, petechiae or ecchymoses, red or brown
urine, swelling skin or subcutaneous, swelling, mass external abdomen,
tachycardia, thoracic swelling. Not all dogs with vWD will show
Diagnosis Diagnosis can be preformed by measurement of
plasma concentrations of vWF. The blood test is called the Von
Willebrand's Factor Assay also known as the Enzyme-Linked
Immunosorbent Assay (ELISA). This blood test is preformed at a
Veterinary Hospital and then sent into a laboratory for a rating of
vWF. Daily variation in vWF can be high, so multiple measurements may
be necessary to establish the Von Willebrand status of a dog.
Hematology Laboratory of Cornell University established the following
Normal range: 70-180% *Considered to be free from vWD, and are
unlikely to transmit the disease
Borderline range: 50-69% *Is equivocal, cannot be classified
definitively but may be clinically or genetically significant.
Abnormal range: 0-49% *May or may not be clinically expressed but
are diagnosed as carriers of vWD and can transmit the trait to
It is believed that dogs testing less than 30% vWF have an
approximately 75% chance of having the clinical signs for vWD
expressed. And dogs testing above 30% have a 25% chance of expressing
Treatment The primary treatment for von Willebrand's
disease is the administration of blood or blood products to patients
with active or anticipated bleeding episodes. A blood product called
cryoprecipitate contains large amounts of von Willebrand factor, but
it is seldom available. More commonly, the veterinarian will use fresh
plasma, or plasma that was frozen immediately after collection and
then thawed. Whole fresh blood may be used if hemorrhage has been
The administration of a drug called DDAVP may be helpful in preventing
hemorrhage in some affected animals if it is given prior to the time
that bleeding occurs. This drug increases levels of von Willebrand
factor available for the clotting process. DDAVP can also be given to
dogs donating blood prior to blood collection, so that samples with
high von Willebrand factor activity can be obtained. Not all dogs
respond to DDAVP.
Care & Prevention Provide soft padded areas for your dog to lie
on. Minimize the chance of injury by observing and fixing any sharp
corners, such as on doggie doors. It is usually not necessary to limit
activity as spontaneous bleeding is not common. If your dog should
begin bleeding, seek veterinary assistance immediately.
Because it is a hereditary disease, an animal born with vWD cannot be
Minimize the chance of injury by keeping your dog
confined either in a fenced area or on a leash when outdoors. If your
dog should begin bleeding, seek veterinary assistance immediately.
Inform any veterinarian treating your dog about his vWD. This is
especially important prior to surgical procedures. Inform any groomer
handling your dog about his condition; they will use extra care in
clipping and trimming nails and can be prepared if a cut occurs.
Since the disease is hereditary, the ideal way to eliminate it would
be to avoid breeding affected dogs. However, not all dogs with low von
Willebrand's factor concentrations have significant bleeding. The mere
fact that the concentration is low does not always mean that
clinically significant problems will occur, even in breeds in which a
significantly high number of dogs have reduced von Willebrand's
factor. If all dogs that tested low for the factor were eliminated
from breeding, then breeding programs would be quite restricted.
Certainly, though, it makes sense not to breed dogs that have had
clinically significant episodes of bleeding due to von Willebrand's
disease, no matter what their breed.
In an affected dog,
problems may be avoided prior to elective surgeries by remembering to
screen for this condition, especially if previous bleeding episodes
have occurred or if there is a familial history of bleeding.
Pre-treatment with DDAVP may help avert disastrous consequences, as
will having blood products on hand in case they are needed.