Prepared by the BHCA Education Committee
All quotations are taken from reports of the NY State Dept. of Health. This article was written by Carolyn Young and is reprinted on this web site with her permission.
What Causes Excessive Bleeding?
There are four reasons for excessive bleeding to occur:
- there may be a lack of platelets in the blood,
- latelets may have been exposed to drugs which prevent them from functioning normally, (e.g.., aspirin),
- The blood plasma may lack factors which are necessary to make the platelets "stick" to the blood vessel wall (as in vWD), and
- The platelets may have a defect that prevents them from functioning normally (as in Canine Thrombopathia).
Why Do Bassets Bleed?
There are two bleeding diseases found in the Basset Hound. One is vonWillebrand's Disease (vWD) and the other is Canine Thrombopathia (CTP). The two diseases are different and a Basset may have either or both in varying degrees. Each is potentially life threatening.
What's the Difference?
Von Willebrand's Disease is found in man, dogs and some other animals as well. IN Bassets it is known that the disease may be inherited or may be acquired. Researchers suggest a relationship between vWD and hypothyroidism which is prevalent in Bassets. Testing will quantify the %vWF:Ag but will not differentiate between the hereditary and acquired forms of the disease. The researchers caution that "carriers of vWD might test as normal when on thyroid medication or animals clear of vWD might test within the carrier range because of underlying hypothyroidism."
"Clinical signs of vW D are caused by a deficiency or abnormality of the von Willebrand's factor (vWF), a protein found in the plasma or liquid portion of blood and also on the surface coat of blood platelets."
Between 1979 and 1989, there were 1060 valid tests performed at the N.Y. State Dept. of Health's Albany lab to detect vWD in Basset Hounds. Of those dogs tested 17% were found to be affected with vWD (bleeders), and 49% were in the normal range, leaving 34% in the borderline range.
Canine Thrombopathia is a platelet dysfunction. When working properly platelets circulate in the blood in great numbers and "clump together" (aggregate) when a chemical "signal" is received from the site of the injury to form "plugs" in blood vessel walls. They also speed up the formation of blood clot. It is the combination of clotting and "plugging" that act to prevent blood loss.
Through 1987 the Albany lab had tested 278 Basset Hounds and of that number found 30% to be either severely or moderately affected with the disease. Other dogs have been tested at Michigan State University and at several other locations throughout the U.S. and Canada. Both diseases have been identified in kennels across the country.
What Should I Look For?
The symptoms for each are the same:
- Bleeding from the gums or other mucosal surfaces including nosebleeds
- Prolonged seasons
- Lameness mimicking panosteitis
- Blood present in urine or feces, including recurrent bloody diarrhea
- Prolonged bleeding -- when cutting nails, with loss of puppy teeth, when cutting the umbilical cord, following dew claw removal, during or following whelping, etc.
- Red spots on a pup's tummy (subcutaneous hemorrhages, known as petechia)
- Stillbirths or "fading" pups, with evidence of bleeding at necropsy
- Severe bleeding or death with surgery
Could My Dogs Be Affected?
The only way to know for sure is by testing.
Testing for von Willebrand's Disease (vWD) is relatively easy. Your own vet can draw a blood sample and send it out to a lab for analysis. If the local lab is unable to process it, they may choose to send it to the N.Y. State Dept. of Health lab at Albany which processes approximately 6000 vWD tests each year for all breeds.
Your results will be given as a Percent "vWF:Ag". The Albany lab defines the normal range to be 70-180%vWF:Ag, the abnormal range 0-49%vWF:Ag, and the borderline range as 50-69%.
Testing for Canine Thrombopathia may be difficult to do depending upon where you live. Definitive testing requires specialized equipment and a highly trained staff. It is limited to only a few labs at this time. Because the blood cannot be drawn more than an hour or two before it is processed this precludes shipping samples from your local vet. Those labs known to be doing reliable testing at the current time include:
James Catalfamo, PhD
NY State Dept of Health
Wadsworth Center for Labs & Research
Albany, NY 12201
Tom Bell, DVM
Michigan State University
A622 East Fee Hall
Michigan State University
East Lansing, MI 48824
Mary K. Boudreaux, DVM, PhD
School of Veterinary Medicine
Dept. of Pathology
166 Greene Hall
Auburn University, AL 36849-5519
There may be other labs that can reliably test but which are unknown to BHCA's Education Committee members at this time. Contact your nearest school of Veterinary Medicine for information or contact one of the labs above for possible referrals.
When Can I Test?
A dog may be reliably tested at any time after 7-8 weeks of age. However, dogs should NOT be tested if:
- Immunizations or medication have been given within the two weeks prior to testing
- Bitches are in season, pregnant, nursing their pups or in a false pregnancy
- The animal is sick
Could the Test Results Be Invalid?
As in human medicine, test results are occasionally invalid. Any of the conditions cited above could make a test invalid. In addition problems in drawing the blood or in shipment may occur. A retest may be recommended.
What If My Animal Is Affected?
A good breeding program does not have to end because you have an animal that carries the genes responsible for either Canine Thrombopathia or von Willebrand's Disease.
While clinically affected animals (i.e., bleeders) should not be used for breeding, carriers (those not clinically affected) can safely be bred if they are mated to animals testing within the normal range. Puppies resulting from such a breeding should be tested at the earliest possible time.