Von Willebrand's Disease

Von Willebrand's disease (vWD) is the most common inherited bleeding disorder of both man and animals.  It is caused by a deficiency in the amount of protein (von Willebrand factor antigen) that is needed in order help the platelets clot.  If the platelets cannot clot properly, they cannot seal broken blood vessels, thus leading to abnormal bleeding.

Breeds Affected by this Disease

There are approximately 30 different breeds known to be affected.  However, Doberman Pinschers are one of the most commonly affected breeds.  In one study, out of 15,000 Doberman Pinschers screened for vWD, more than 70% were found to be carriers of the disease.  Luckily, most of the dogs are not clinically affected, meaning that there is no evidence of bleeding problems.  Unfortunately, the number of Doberman Pinschers with a history of bleeding problems seems to be on the rise.  Any breed of dog can have vWD, but vWD is more commonly seen in the breeds listed below.

• Cairn Terrier
• Chesapeake Bay Retriever
• Doberman Pinscher
• German Shepherd Dog
• German Shorthaired Pointer
• Giant and Miniature Schnauzer
• Greyhound
• Golden Retriever
• Scottish Terrier
• Shetland Sheepdog
• Shih Tzu
• Siberian Husky
• Standard Poodle

Signs Seen in my dog

Many dogs with vWD will never show outward signs of having the disease.  Other dogs will have outward signs of bleeding such as bleeding from the nose, vagina, urethra, or gums.  They can also have prolonged bleeding after trauma or surgery.  Females can bleed excessively after giving birth.  Affected dogs can bleed to death if the hemorrhage is severe and/or cannot be controlled.

How von Willebrand's Disease is Diagnosed

Von Willebrand's disease is diagnosed by running a blood test to measure von Willebrand factor.  This helps diagnose carriers as well as affected animals.  A preliminary test, called a buccal mucosal bleeding time, can be run on animals prior to surgery.  If this bleeding test is abnormal, that can send up a red flag that there is a clotting problem and the veterinarian can consult with you regarding further testing.  It has also been shown that hypothyroid dogs can have "acquired" vWD and once the thyroid levels are normal.  Owners of Dobermans often report that the pet has undergone a spay or neuter without any bleeding problems.  An uncomplicated recovery from such procedures does not eliminate the possibility that a dog may have vWD; some dogs do not become obvious "bleeders" until later in life.

Medications to be avoided

Certain medications should be avoided in dogs with known vWD.  The drugs listed below can precipitate a bleeding crisis in affected dogs.

• Aspirin
• Antihistamines
• Ibuprofen (no dog should have this drug at any rate)
• Ampicillin
• Amoxicillin
• Phenothiazine tranquilizers
• Theophylline
• Heparin
• Penicillin
• Estrogens
• Sulfa-based antibiotics
• Phenylbutazone

Treatment of vWD

There are no medications to correct vWD.  In an emergency situation, transfusion of blood of fresh frozen plasma can stabilize a dog.  The donor dog may be given a drug called DDAVP prior to blood collection.  DDAVP raises the level of von Willebrand factor in the donor's blood, thus benefiting the dog receiving the blood transfusion.  In dogs with known vWD, DDAVP can be given to the dog prior to any known surgery.  DDAVP is NOT used on a regular basis in order to correct vWD.

If you own any of the breeds mentioned above, talk to your veterinarian about doing a von Willebrand factor screening test in your dog, especially if you are going to breed your dog.  Knowing that your dog has vWD is greatly beneficial if you dog gets injured or needs surgery; dogs with vWD should not be used for breeding.

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