Von Willebrand's disease, often abbreviated as vWD is a hereditary blood disorder in dogs that leads to excessive bleeding. Von Willebrand's disease is very similar to hemophilia in humans and while controllable and manageable can be fatal under certain conditions.
Any breed of dog can have von Willebrand's disease but some breeds are more prone to having the genetic factors for the condition than others. Larger breeds such as German Shepherds, Chesapeake Bay Retrievers, Doberman Pinschers, Golden Retrievers, German Shorthaired Pointers, Airedale Terriers, Keeshonds and Standard Poodles are more prone to having the condition whereas some of the medium to small sized dogs such as Shetland Sheepdogs, Dachshunds, Corgis and Scottish Terriers also have a higher than average rate of von Willebrand's disease indicating it can also be a breed specific condition. Males and females are equally likely to have the condition and many dogs may go undiagnosed their entire life if they do not have any injuries or other related health problems.
What is von Willebrand's disease?
Dogs with von Willebrand's disease do not have the necessary clotting agents in the blood so when cut or injured either internally or externally they will bleed excessively and often will need first aid and assistance to stop the bleeding. In normal dogs without von Willebrand's disease when a dog is cut the nerves signal the brain to release a precursor material that then triggers the production of a clotting agent called Factor I. This is the first in a step of chemical reactions in the blood that lead to the formation of a blood clot at a wound or injury site. There are actually twelve such factors that lead to the binding of the platelets at the injury site to cause the blood to clot. Dogs with von Willebrand's disease are missing the 8th factor in the chain called Factor VIII. The chain reaction proceeds perfectly normally up to the eighth step then simply stops because the required factor is not present to continue the chain reaction. The platelets are also present in the blood but simply cannot be bound by the chain reaction to form the clot.
Dogs may be a carrier of von Willebrand's disease and still have normal blood clotting abilities of their own. In cases where these dogs than breed with another dog that is either positively tested for von Willebrand's disease or is a recessive carrier, the litter will have von Willebrand's disease. The best option is to have all males and females used in breeding programs tested for von Willebrand's disease, especially in high risk breeds as listed above.
What are the symptoms of von Willebrand's disease?
Basically a dog owner will not be aware that their dog or puppy has von Willebrand's disease until he or she is hurt in either an accident or has some type of injury that causes internal or external bleeding. For many puppy owners the first time they hear of the disease is from the vet that spayed or neutered the puppy or young dog and noted that the blood did not clot without medical intervention.
For some dogs there may also be other telltale signs even if the dog is not hurt or in an accident, fight or surgical procedure. Bleeding around the gums when the puppy is not teething or nosebleeds are the common indicators in puppies. In addition observant owners may notice blood or bloody streaks in the urine or in the fecal material. Often the feces are tarry and black indicating bleeding in the stomach and digestive tract. Adult dogs may also have the same types of symptoms as well as heavy bloody discharge when the females are in heat as well as bleeding from the penis or vagina when the male or female are not in the reproductive cycle. For females with von Willebrand's disease whelping or birthing a litter of puppies can be a particularly hazardous time and they should be closely supervised both during and after labor to ensure that all bleeding has stopped.
Occasionally in light skinned dogs discoloration or swelling of the skin can indicate sub-dermal bleeding, which may cause sensitivity in the area. Scratching by the dog can then lead to hemorrhaging which can be very serious if not treated immediately. Sometimes even a simple nail trimming where the quick is cut with the trimmers can result in excessive and serious bleeding, especially for tiny puppies and small breeds.
How is von Willebrand's disease treated?
As a genetic condition there is no cure or treatment for von Willebrand's disease, rather owners of dogs with the condition must learn some management techniques as well as what to do in the case of an injury.
A vet will assess the severity of von Willebrand's disease to determine the treatments options and management needed. Most dogs will have a type I diagnosis which means the von Willebrand's factor is very low resulting in poor clotting of the blood. This is assessed through blood tests, clotting tests and urine analysis to check for blood. Type II von Willebrand's disease is very rare and type III is the most significant and severe.
Owners must notify anyone treating or prescribing medication for the dog that he or she has been diagnosed with von Willebrand's disease as some medications such as aspirin or sulfa or penicillin based antibiotics, antihistamines and even some tranquillizers can further decrease the blood's ability to clot.
In some dogs thyroid medication can help to increase the von Willebrand's factor in the blood as can a medication called DDAVP that is now being used more frequently with the type III or very severe dogs. Most dogs with von Willebrand's disease will have a very normal life but should never be used in any type of breeding program.
Owners of high risk breeds should have puppies tested and then again have adult dogs tested at about two years of age. There are some reports that in some breeds, particularly in Dobermans, the condition does not appear to be problematic until the dogs are fully mature.
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