Interpreting DNA Test Results for Von Willebrands Disease
(Information via Vet-Gen)
What is von Willebrand's disease?
Von Willebrand's disease (vWD) is a common, usually mild, inherited bleeding disorder in people and in dogs. It is caused by a lack of von Willebrand factor (vWF), which plays an essential role in the blood clotting process.
Normally the body responds to an injury causing bleeding through a complex defence system. This consists of local changes in the damaged blood vessels, activation of blood cells called platelets, and the coagulation process. A reduction in von Willebrand factor leads to abnormal platelet function and prolonged bleeding times.
Three forms of the disease are distinguished based on vWF concentration and function. Dogs with Type I vWD (by far the most common) have mild to moderate bleeding abnormalities, depending on the level of vWF. The much rarer types II and III vWD cause severe bleeding disorders.
von Willebrand's Disease:
Unfortunately, there is no such thing as a perfect dog of ANY breed. Canine geneticists estimate that the average purebred dog is carrying at least 4-5 defective genes, even grand champions. Today’s breeders make the best breeding decisions they can based upon testing results, conformation, temperament, working ability, pedigree, etc. A good breeder is open and honest about the health status of all their dogs and is always willing to help and guide the new puppy owner.
von Willebrand's Disease is one of the least destructive diseases inherited by Dobermans but it should not be ignored. It is a genetically inherited autosomal recessive bleeding disorder much like hemophilia and is the most common bleeding disorder in canines and in humans. It affects some 60 different breeds of dogs including the Doberman Pinschers and Sheltie's and because it is genetic in nature, there is no cure only eradication by deliberate breeding strategies. It is passed on directly from one generation to the next and will affect offspring to varying degrees.
Although Dobermans are one of the breeds most commonly affected by von Willebrand's, they usually have only the milder form (Type I). Other breeds suffer from type II (moderate to severe form and extremely rare being found only in German Shorthaired Pointers and German Wirehaired Pointers) and still others are well known to suffer from type III (severe but rare).
Under normal circumstances, type I means that bleeding will clot normally. However, in times of stress or with major blood loss during surgery or as a result of trauma, the defect may become “clinically” apparent with the inability to clot. Bleeding tendencies can be exacerbated by medications or by stress such as illness, particularly viral disease since viral infections can prolong clotting times by impairing platelet cohesiveness and/or endothelial cell production in the blood vessel walls (the endothelial cells produce the protein called von Willebrand's factor which is necessary for normal clotting). Because Parvovirus attacks the gastrointestinal tract where it causes bleeding, it is especially dangerous to Dobermans. Live virus vaccines can have the same effect.
There are 3 classifications of type I vWD dogs: Clear, Carrier and Affected. As of January 2004, VetGen states that of the Dobermans it has tested, 25% of Dobermans were classified as clear, 49% were carriers and 26% were classified as affected.
What breeds are affected by von Willebrand's disease?
Type I vWD: This is by far the most common form. The gene for the condition is widespread in the Doberman pinscher population, and is also relatively common in the Scottish terrier and Shetland sheep dog. There is an increased risk of the disorder in the Golden retriever, standard and miniature poodle, Welsh Pembroke corgi, miniature Schnauzer, basset hound, German shepherd, Rottweilers, Manchester terrier, Keeshond, and standard and miniature dachshund. This disease occurs in most other breeds and in mixed-breed dogs as well.
Type II: extremely rare, German short-haired pointer
Type III: rare, occurs in the Scottish terrier, Shetland sheepdog, and very sporadically.
What does von Willebrand's disease mean to your dog & you?
Although many dogs are affected by vWD, only a small proportion have any problems. Some dogs with vWD are prone to nose bleeds, bleeding from the gums, and prolonged bleeding during heat or after whelping. There may be prolonged bleeding from the umbilical cord at birth or when your pup sheds its baby teeth. Excessive bleeding after surgery or trauma is common, and may be the first sign of this condition in your dog. You may see blood in your dog's urine or stool.
Most dogs with vWD lead normal lives (and many are un-affected by these syptoms) with occasional bleeding episodes that may go unnoticed or can be treated appropriately.
How is von Willebrand's disease diagnosed?
There are specialized tests available to make the diagnosis of von Willebrand's disease. One is a genetic test and the other measures blood levels of von Willebrand factor.
The trait for von Willebrand's disease is widespread, particularly in Doberman pinschers but also in several other breeds. An accurate genetic test has been developed for the Doberman pinscher, Scottish terrier, Shetland sheepdog, Manchester terrier, poodle, and Pembroke Welsh corgi. Testing can reliably identify dogs with vWD, dogs that are carriers, or dogs that are clear.
There are three possible test results: Clear, Carrier, and Affected.
Below is a description of what each result means to you as a owner/breeder.
CLEAR: This finding indicates that the gene is not present in your dog.
Therefore, when used for breeding, a Clear dog will not pass on the disease gene.
CARRIER: This finding indicates that one copy of the disease gene is present in your dog, but that it will not exhibit disease symptoms. Carriers will not have medical problems as a result. Dogs with Carrier status can be enjoyed without the fear of developing medical problems but when bred will pass on the disease gene to 50% of thier offspring.
AFFECTED: This finding indicates that two copies of the disease gene are present in the dog. These dogs always have a potential to bleed given the right circumstance and will always pass on the disease gene (mutation) to their progeny.
Please see the following page, and follow all the links for more detailed information. http://www.vetgen.com/vwdrpt.html Also, inform your veterinarian and consult with him/her regarding this test result.
VetGen's DNA test findings can be extremely valuable when developing and implementing your breeding plans.
The chart provided below outlines the implications of various breeding pair combinations. Remember, it is always best to breed "Clear to Clear". If followed by all breeders, these strategies will ensure a significant reduction in the frequency of the targeted disease gene in future generations of dogs. However, to maintain a large enough pool of good breeding stock, it is necessary for some breeders to breed "Clear" to "Carriers" (see below).
Breeding Pair Combinations:
Ideal Breeding Pair. Puppies will not have the disease gene (neither as Carrier nor as Affected).
Breeding Is Safe. No Affected puppies will be produced. However, some or all puppies will be Carriers. Accordingly, it is recommended that Carrier dogs which are desirable for breeding be bred with Clear dogs in the future, which will produce 50% carrier and 50% clear animals, to further reduce the disease gene frequency. These offspring should be tested by VetGen's test for this defective gene, and if possible, only the clear animals in this generation should be used.
High Risk Breeding. Some puppies are likely to be Carriers and some puppies are likely to be Affected. Even though it is possible that there will be some clear puppies when breeding "Carrier to Carrier", in general, neither this type of breeding pair nor "Carrier to Affected" are recommended for breeding.
Breeding Not Recommended. All puppies will be genetically Affected.
Dilated Cardiomyopathy (DCM)
What is dilated cardiomyopathy?
Different types of heart disease are characterized by which part of the heart is abnormal or affected and in what way. In the case of cardiomyopathy, the abnormality involves the heart muscles itself. In dilated cardiomyopathy (DCM), specifically, the muscle wall of the heart becomes thin which results in a bigger but weaker heart that is not efficient at pumping blood.Click here to learn more about dilated cardiomyopathy basics.
Are Dobermans at a greater risk for dilated cardiomyopathy?
In dogs, DCM occurs at a higher incidence in specific breeds including the Doberman pinscher. While there are likely multiple factors that combine to produce clinical DCM, the fact that the disorder occurs at a higher incidence in specific breeds has always suggested that there is a heritable genetic component to this disease, says Cornell University College of Veterinary Medicine.
Testing for dilated cardiomyopathy in Dobermans
Dr. Kathryn Meurs, of NC State, has identified one gene mutation that is responsible for the disease. However, since there could be other mutations involved as well, research is ongoing. For now, though, you can have your Doberman tested for the presence of this one mutation. You just need to keep in mind that a negative test does not completely rule out the possibility of your dog developing DCM (since I already mentioned that there are likely other factors and/or mutations involved). Also, a positive test does not always mean your dog will develop the disease. Please note there are no accurate tests, or cure available at this time. Even with yearly holters there is no guaranteed testing, further research is needed. Note that breeders who support DCM tests are contributing to help scientist and geneticist further their research.
Regardless of any genetic test results, to protect your dog, awareness and vigilance are the key.
Symptoms of dilated cardiomyopathy in Dobermans
The symptoms of DCM depend on which ‘form’ of the disease manifests. Some dogs develop congestive heart failure as the weakened muscle fails to adequately propel blood forward, resulting in:
Pressure and fluid backs up into the lungs causing:
Or even into the abdomen causing:
Some dogs develop cardiac arrhythmias (abnormal beats and irregular rhythms) that can cause sudden death1.
What are the breeds most commonly affected?
Dobermans and Great Danes are the breeds most commonly affected. A recent survey of the Veterinary Medical Database showed that 4.2% of Great Danes have wobblers, whereas the disease is present in 5.5% of Dobermans. Dobermans usually have the classic form of the disease in large breed dogs whereas Great Danes have the typical form seen in Giant breeds. Other breeds are Rottweilers, Mastiffs, Weimaraners, German Shepherds, Bernese Mountain dogs, Swiss Mountain dogs, but any large or giant breed dog can have the disease.
Is the disease the same in Dobermans and Great Danes?
Generally speaking no, the disease tends to be different in these breeds. Dobermans usually have the disease when they are middle aged to older (mean age 6 years), whereas Great Danes are typically younger (mean age 3 years).
What causes the disease?
We don’t know yet what exactly causes the disease. Many people believe that there is a genetic basis for the disease, which may well be true, but the evidence for genetics is still not clear. We are investigating the genetics of the disease in Dobermans and have plans to study it in Great Danes in the future.
Wobblers syndrome is caused by a narrowing or malformation of the spinal cervical (neck) vertebrae which causes pressure on the spinal cord by the lower cervical (neck) vertebrae due to either a malformation of the vertebra or a malocclusion (when the vertebrae do not come together properly). This causes anywhere from a mild, to a severe affect in the dogs gait.. Other conditions can mimic the symptoms. The only definitive diagnosis of Wobblers Syndrome or Spondololithesis, is a mylogram where dye is injected into the spinal column and then the neck is flexed and x-rayed.
Breeds affected: - Dobermans and Great Danes primarily - young Danes more commonly affected. Dobermans - young and old, can grow through the problem as youngsters, more commonly seen in middle aged to older Dobermans (3 to 9 years of age) Other breeds who have a similar if not identical syndrome described include the Boxer, Basset, Bull Mastiff, St. Bernard, Weimeraner, Labrador Retriever, German Shepherd, Rhodesian Ridgeback, Dalmatian, Samoyed, Old English Sheepdog, Irish Setter, and the Borzoi. Males are affected more often, in a ratio of 2:1
The cause of Wobblers Syndrome is unknown, although a link to fast growth and genetics is suspected. According to the Merck Veterinary Manual, "The cause is unknown, although rapid growth rates and nutrition, mechanical factors, and genetics may be implicated." Some breeders say that there has been a marked decrease in the incidence of not only Wobblers Syndrome, but other diseases that occur during the early, fast growth stages of Great Danes, when weight is kept down and growth rate has been slowed nutritionally.
Symptoms usually appear first in the rear legs as a mild uncoordination in gait (ataxia) and can escalate to involvement of the forelegs as well. The severely affected dog moves like a drunk and the uncoordination shows up most when the dog is walked and then moved sharply into a turn. An unsuspecting owner might simply conclude that his older puppy was just clumsy. Overly clumsy young Great Danes should be Wobbler suspects.
In Great Danes, Wobblers Syndrome most commonly appears from 10 months to a year and a half of age although it can manifest as old as 4 or 5 years, and as young as 5 weeks. In Doberman Pinschers it usually doesn't appear until the dog is 4 or 5 years old.
A veterinarian will do a neurological work up on the dog and this often includes not only cervical spine x-rays, but a mylogram x-ray. A mylogram is not only dangerous to the dog, but is expensive. The owner should thoroughly investigate the advisability of this procedure, especially since if it is Wobblers Syndrome, surgery may not be the best option.
Treatment of Wobblers Syndrome can include the use of corticosteroids, a neck brace and surgery. The surgery fuses the 2 unstable vertebrae which relieves the pressure on the spinal cord. Unfortunately this also puts further stress on adjoining vertebrae which can cause instability to recur in them. Many Wobblers can live a long and pain free life with little or no treatment. Others deteriorate quickly and euthanasia then becomes the only kind choice.
Doberman Pinschers are considered by their owners to be reliable family pets. Dobermans were first bred in Germany to serve as guard dogs. Once known to be a very aggressive breed, the Doberman’s temperament has improved through breeding over the years and is now considered a generally non-aggressive dog.
The Doberman’s powerful, muscular build gives it speed, elegance, strength, and endurance. Its posture is alert and proud, and its gait is fast. Dobermans come in a color range of black, blue, fawn, red, and a light yellowish brown. Above each eye are rust-colored markings which also appear on the muzzle, throat and chest, below the tail, and on all four legs and feet. The Doberman has a smooth, short coat with neat lines and a white patch on its chest.
Dobermans are adventurous and loyal companions. They make talented and obedient students when they are being trained. They are usually sensitive and responsive to an owner’s commands, but they can also be dominating and overbearing. The breed is usually shy with strangers, but become aggressive with strange dogs. Owners who choose a Doberman usually do so for their alertness and ability to protect their owners from possible harm.
Dobermans require mental and physical exercise daily or they can become destructive or frustrated. A walk on a leash, a run in an enclosed area, or a long jog generally satisfies their need for activity. Dobermans are most useful indoors as a guardian and a family companion. Their coats require minimal care which means you don’t have to worry about shedding hair all over the house and the furniture.
The history of Doberman Pinschers is very interesting. A German tax collector named Louis Dobermann is credited for the breeding the first Doberman Pinscher. He was searching for an attentive guard dog to accompany him on his rounds, and in the late 19th century he began to experiment by crossing the German shorthaired shepherd and the German Pinscher.
The original Dobermans had round heads and heavy-boned bodies, but breeders soon began to develop a more robust-looking dog. Over time, the breed evolved and by 1899, the National Dobermann Pinscher Club was created in Germany.
The first Doberman Pinscher was brought to the United States in 1908. Utilized as a guard dog, police dog and a war dog, the Doberman’s qualities made it a favorite as a family bodyguard.
In 1977, the Doberman became the second most popular breed in the United States. Since then, the breed has kept its well-regarded status as both a guard dog and a family pet.
Doberman Pinschers have a lifespan of 10 to 12 years.
Wobbler’s syndrome, cervical vertebral instability (CVI), and cardiomyopathy are some serious health problems affecting Dobermans, as well as canine hip dysplasia.
Hip dysplasia in Doberman Pinschers
Symptoms of hip dysplasia in Doberman Pinschers include moving more slowly, difficulty in getting up or lying down, reluctance to walk, jump or play, refusing to use stairs or get into the car, muscle atrophy, limping, yelping when touched, changes in appetite, and personality changes.
Dobermans who develop hip dysplasia, arthritis or osteochondrosis (OCD), suffer from pain and stiffness in their joints, and their ability to live a quality life and remain active is greatly diminished.
Treatment & Prevention
When a Doberman is diagnosed with hip dysplasia and the choices for treatment seem limited to expensive surgery or questionable drugs, I recommend you begin treating your dog with Winston’s Joint System, an all-natural formula developed by a Naturopathic Doctor to heal his own beloved dog. This proven formula has been giving relief from pain and stiffness to all breeds and ages of dogs for more than 20 years.
Because hip dysplasia is primarily an inherited condition in Dobermans, there are no products that can prevent its development.
However, you can slow, and sometimes halt, the progression of the disease.
There are different assumptions on how to prevent the progression of hip dysplasia in Doberman Pinschers. Poor nutrition, inadequate or improper exercise, and increased body weight may all contribute to the severity of osteoarthritis after the hip dysplasia has developed.
By watching the calories your puppy or young dog consumes and preventing obesity in your dog, allowing only non-stressful types of exercise, and a daily regimen ofWinston’s Joint System, are the best things you can do for your dog.
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Symptoms can vary from one case to the other.
- The condition is called autoimmune thyroiditis. The tyroid is attacked by antibodies, these antibodies normally just fight infection.
- Signs typically show between 4 and 6 years old.
- One or more symptoms can show.
Behavioral changes: aggression, irritable, anxiety and/or compulsivity
Dull and/or Thin Coat
Hair loss on around tail and hips and/or limbs
Hair Loss in general, "Moth eaten" coat
Extra "Eye Buggers"
Skin Infection (Pyodermia)
High blood cholesterol
Slow heart rate (bradycardia) *
Cardiac Arrhythias *
Diagnosised: Blood work is taken by your vet after the dog is fasted for 12 hours. If the level of T4 is low, they may do a TSH test to make sure.
Treatment: Treatment is with hormone replacement medication given every 12 hours. The test will need to be repeated in 1 to 2 weeks to make sure the medication is at the right level. If it is still off, try switching brand names before increase the dose. Different brand names aborb differently. Soloxine (link) has been said to aborb well. After the medicine is stable, they are usually retested every 6 to 12 months. Typicaly the dog is on treatment the rest of their life. Within a couple weeks after the medicine is stable, you should start to notice improvement!
* Being a Doberman owner, I was excited when I heard this. Something else but DCM causing the VPCs.... No :( That thought was short lived. What had my hopes up was, that hypothyroidism interfers with the electrical fibers making up the heart. Rhythmic contractions are normally stiumulated by these fibers. From talking with two doctors, they agreed that being hypothyroid can make the heart worse faster, but it has not been known to cause DCM.
Thyroid medicine should be given at lower the lowest dose possible for patients with heart diesease. To much can have more side effects.
If there is not enough thyroid hormones being produced, it affects the metabolic function of most the organ systems. Abnormalities related to the cardiovascular system are not common. There is little evidense that supports one causing the other though.