A deficiency of vWF causes Von Willebrand’s disease. vWF is an adhesive glycoprotein in the blood which accounts for normal platelet binding during blood vessel injuries. Also, vWF is a carrier protein for another important coagulating substance called Factor VIII. That's why a lack of vWF can cause excessive bleeding in any type of injuries.
What is Von Willebrand’s disease in dogs?
“Von Willebrand's disease (vWD) is the most common inherited bleeding disorder of both humans and dogs”, said Dr Ernest Ward. Whenever vWF is lacking inside a dog’s body, his immune system has a substantial difficulty to form clots. In a way, it resembles haemophilia in humans. Von Willebrand Factor is an autosomal characteristic. Dogs (male and female) transmit their vWF genes with equal frequency. Generally, Von Willebrand’s disease in dogs has severe forms (Types 2 and 3 vWD) and a milder form (Type 1 vWD).
Which dog breeds are commonly affected by Von Willebrand’s disease?
“At least thirty different breeds are affected but the Doberman pinscher is the breed with the highest incidence of vWD. Of 15,000 Dobermans screened in a research study, more than 70% were carriers of the disease”, said Dr Ward. Even though these test subjects did not display symptoms of the disease, numbers show that infection is on the rise.
Fortunately, studies also showed that Dobermans usually have the mildest form of this disease. “Another study showed that 30% of Scottish terriers and 28% of Shetland sheepdogs had abnormally low concentrations of von Willebrand factor. Chesapeake Bay Retrievers and Scottish terriers get the most severe form of the disease”, said Dr Ward. If you have any of these dog breeds, you need to wait until the age of four to get a proper diagnosis.
Symptoms of Von Willebrand’s disease in dogs
Von Willebrand’s disease in dogs can never actually manifest! Nonetheless, according to vets, bruising or bleeding after a surgical sterilisation procedure are the first abnormalities. Other common symptoms are:
- Spontaneous haemorrhage from mucosal surfaces: nosebleeds, blood in the faeces (black or bright red blood), bloody urine, bleeding from the gums, bleeding from the vagina (excessively)
- Bruising of skin
- Prolonged bleeding after surgery or trauma
- Blood loss anaemia
Diagnosing Von Willebrand’s disease in dogs
Vets commonly carry out a screening test called ‘buccal mucosal screening test’. Prolonged bleeding with this test can raise suspicion of this disease. “To confirm the diagnosis, the exact amount of von Willebrand factor present in the blood can be determined through a very accurate laboratory blood test”, said Dr Ward.
Likewise, Dobermans have a risk of getting this disease since puppyhood. This dog breed undergoes the routine surgical procedure of having his tail cut. If they have a complicated recovery, then the pup has a possibility of having VWD in the future.
What can increase the risk of Von Willebrand’s disease in dogs?
If you have a dog breed like those previously mentioned, it is vital to avoid some drugs that may induce a bleeding crisis! Here you have a list:
- Aspirin
- Antihistamines
- Sulpha-based antibiotics
- Ibuprofen
- Oestrogens
- Ampicillin/Amoxicillin
- Penicillin
- Phenothiazine tranquillizers
- Heparin
- Theophylline
Also, stress encourages bleeding. “Clients with dogs diagnosed with VWD should try to maintain a stress-free lifestyle, and the dog should be monitored closely for bruising or bleeding if they travel, have houseguests or other stressful events occur”, said Dr Ward.
Treatment of Von Willebrand’s disease in dogs
This disease has no cure. But, vets can treat the symptoms. In most cases, a transfusion of blood or frozen plasma stabilises a bleeding dog. Usually, vets inject a drug called DDAVP to the dog donating blood prior to blood collection. This drug will raise the level of von Willebrand factor in blood thus benefiting the dog with VWD.
In the case of mild Von Willebrand’s disease in dogs, some pets are able to increase the amount of vWF in circulation after the administration of DDAVP. Nonetheless, it is not advisable to use this drug regularly. “The drug is expensive, and not all dogs will respond to it. Your veterinarian will discuss the treatment option and help you decide if it is an appropriate option for your pet's condition”, said Dr Ward. Von Willebrand’s disease in dogs is a serious disorder. Finally, you need to be careful of your pet after the age of 4!
