|
Von Willebrand's Disease is a common inherited bleeding disorder.
Clotting is a complex mechanism. In addition to platelets, clot formation is the result of a long chain of chemical reactions carried out by individual molecules called 'clotting factors.' Each factor is numbered such that factor I leads to a reaction with factor II forming a new substance. This then reacts with factor III and so on to factor XII.
In Von Willebrand's Disease, the dog is missing a substance, which helps the platelets form clots and stabilizes Factor VIII in the clotting process. This substance is called 'Von Willebrand's factor.' Because of the deficient clotting of blood, dogs with Von Willebrand's disease have excessive bleeding upon injury. This would be similar to hemophilia in humans.
What are the Symptoms?
Excessive bleeding is the main symptom. Bleeding generally occurs after a wound or surgery. In severe cases puppies will bleed excessively after getting their tails docked, dew claws removed or loosing their puppy teeth. In these cases, the blood simply does not clot in the normal time, and bleeding is extensive. Dog's with Von Willebrand's disease may also develop nosebleeds, or bleeding from the gums. Bleeding may also occur in the stomach or intestine in which case the stool may either have blood in it, or be black and tarry. Some dogs will have blood in their urine. Bleeding into the joints also occurs, which can cause symptoms similar to those of arthritis.
The diagnosis of Von Willebrand's is made through a test, which checks for the level of Von Willebrand's factor in the blood.
What are the Risks?
These dogs, without treatment, can bleed to death following surgery, or what might be normally considered less than life threatening injuries.
What is the Management?
A transfusion with blood collected from normal dogs is the only proven way to treat Von Willebrand's disease. Some dogs with Von Willebrand's disease also are hypothyroid - meaning they have lower than normal levels of thyroid hormone. These dogs will benefit from thyroid hormone replacement therapy.
There is no cure for Von Willebrand's disease. Prevention through eliminating affected Weimaraners from any breeding program is the goal of veterinary medicine today. Tests are available to determine which dogs may have this trait. All dogs with a history of this disorder in their backgrounds should be tested. If testing is positive, the dog should not be bred.
Doctors Fosters & Smith Peteducation.com
|
