SALUKI HEALTH - VON WILLEBRAND'S DISEASE The effect of this disease on dogs is that the natural healing of cuts and wounds fails to function properly so that bleeding can carry on for a very long time. This means that every scratch can be life threatening and internal bleeding can occur spontaneously without any obvious cause. It is the same sort of thing as the haemophilia which afflicted the royal families of Europe in the last century, being due presumably to excessive interbreeding (just like dogs). Dogs can also be afflicted with haemophilia but von Willebrand's disease (vWd) is much more common, having been diagnosed in over fifty different breeds, including Salukis. In an extensive screening programme carried out at the Veterinary Hematology Laboratory in Albany, New York, 73% of Dobermans tested in 1988 were found to be carriers of the disease, 43% of Pembroke Corgis, 30% of Scotties, 28% of Shelties, 27% of Golden Retrievers and 26% of Standard Poodles. Last year a Saluki bitch in the UK tragically died after a heart-breaking sequence of crises brought on by almost unstoppable bleeding, showing all the symptoms of vWd.
Sometimes these symptoms appear at birth with the result that puppies are born dead, or die in the uterus and get reabsorbed. In other dogs, excessive bleeding does not occur until their system receives a shock, such as in surgery or whelping. Some get away with it altogether. Only 1O-20% of Dobermans, identified as carriers of vWd at Albany, had shown any inclination towards abnormal bleeding up to that point. Puppies may, apparently, show some increase in bleeding after dew-claw removal but later experience massive haemorrhage if they are subjected to surgery or extreme stress.
vWd is caused when a protein (called, not surprisingly, the von Willebrand factor) fails to do its job. This protein, when it is working properly, acts like glue for the blood platelets so that they can stick to the walls of damaged blood vessels and begin the healing process. When the level of this protein in the blood is low (and there is a routine test for this), the dog is diagnosed as being liable to excessive bleeding - the lower the level the worse the risk. Results of the test come back as a percentage (don't ask me why) between 0% and 172%. Any score under 50% is interpreted to mean that the dog has vWd, whether abnormal bleeding has been noticed or not. Above 7O% and the dog is clear. Between 50% and 69% the result is regarded as equivocal (dodgy). Lisa and I have had four of our dogs tested and two of them were pronounced clear and two came out as carriers. (Fortunately neither of these last two has shown any signs of excessive bleeding and neither has been bred from). So, unless the bleeding function in Salukis is different from that in other dogs, vWd is present in English Salukis.
There is also two autoimmune diseases with similar effects to vWd. These are diseases where the dog’s immune system goes bonkers and attacks members of the home team - in this case destroying blood cells.
With thrombocytopaenia (try saying it slowly in front of a mirror) the symptoms are the same as for vWd but tests on the blood will show a very low level of blood platelets (knocked out by the immune system). Haemolytic anaemia is apparently, the most common autoimmune disease in dogs and also leads to the destruction of blood cells, but excessive bleeding does not occur. Further details can be found in the Northern Saluki Club Newsletter of June 1995.
In general, vWd is inherited from sire or dam or both. The mechanism of inheritance is complex (we are getting into the heavy stuff here) because there are, in fact, three types of vWd and each type operates differently. The most common - Type I - is incompletely dominant. That means that a puppy that inherits the affected gene from either its sire or dam can have vWd (that's the dominant bit) or it may not (that's the incomplete bit). In the latter case, the pup is a carrier and can pass the gene on to future offspring. If the puppy inherits the wonky gene from both sire and dam, it will have vWd without any options. Don't forget that the medical test measures the level of one of the healing components actually present in the blood, not the presence of any gene. Unlike haemophilia, both dogs and bitches are subject to the symptoms of vWd if they carry the disease.
All this means that it is important to test for vWd before surgery and before mating. In the first place, knowing whether or not the dog is likely to haemorrhage badly might affect a decision about the advisability of surgery. And, in the second, it would clearly be smart not to mate any bitch or dog which has been scored as having vWd. If, in the interests of the diversity of the breed and the gene base, it is decided to go ahead with the mating of a carrier of vWd, a mate with a high score should be chosen and the puppies tested and the subsequent purchasers informed. There is the accompanying risk, if the bitch is the carrier, of a small litter and of still-births, and even the loss of the bitch through haemorrhage.
Mr. & Mrs A. F. Parnham South Green, Maldon Road, Steeple, Southminster, Essex CM0 7RT. Tel./Fax: 01621 772092 28th November 1997 Full name and address of Dr W Jean Dodds DVM Person packet is to. HEMOPET 17672-A Cowan Suite 300 Irvine CA 92614 United States of America Contact details of addressee Dr W Jean Dodds DVM Telephone Number 714 252 8455 (Blood bank/lab) 310 828 4804 (Home) Fax Number 310 828 8251 Number of pieces in parcel 8 plasma samples, health sheets and one dollar cheque. Total Weight 245 grams Dimensions of Parcel 29cm x 36cm Description of Goods 8 plasma samples of 8 dogs for vWD. Health information sheets. Reason why Exporting Samples. Test unavailable in UK. I declare that the above information is true and correct to the best of my knowledge and that the goods are of UK origin. Signed: Mr. A. F. Parnham.Tony Parnham
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