Current Research Studies - Health - Bernese Mountain Dogs
Portosystemic shunt (PSS) [Liver shunt]
Research Organization: Utrecht University, Netherlands
Contact Information:
United States & Canada
Robert J. Washabau, VMD, PhD, Dipl. ACVIM, Professor of Medicine and Department Chair
Department of Veterinary Clinical Sciences
College of Veterinary Medicine
1352 Boyd Avenue
University of Minnesota
St. Paul, Minnesota 55108
Phone: (612) 625-5273 Office/VoiceMail
Email: washabau@umn.edu
Netherlands & Europe
Jan Rothuizen, Professor of Internal Medicine of Companion Animals
University Utrecht
PO Box 80154
3508 TD Utrecht
Email: J.Rothuizen@vet.uu.nl
Project Web Site: Not applicable
About This Disease
Portosystemic shunt (PSS) is a devastating congenital condition which affects the liver. There are different types of shunts; congenital portosystemic shunt (CPSS) and primary portal vein hypoplasia (PPVH).
The liver is essential in removing many toxins formed in the intestines. Blood from the portal vein is essential for normal liver growth and function. In a dog with a liver shunt, blood from the portal vein does not reach the liver. As a consequence, the liver does not grow to a size commensurate with the body's needs. In the case of a shunt, toxins bypass the filtering processes of the liver to reach the systemic blood circulation and ultimately the brain. One of the most damaging of neurotoxins is ammonia, which when it reaches the brain disrupts normal brain function.
Symptoms of liver shunts in dogs usually show up at an early age.
In some cases, signs of a canine liver shunt don't show up until a dog is older, when kidney and bladder problems, such as stones, develop.
Liver Shunt symptoms include:
- depression
- failure to grow at a normal rate
- behavioral changes (staring into space, circling, and disorientation)
- weakness or lethargy
- seizures
- inability to gain weight
- too much weight gain
- vomiting
- diarrhea
Surgery is the only long-term treatment, but is not always successful.
In Bernese Mountain Dogs the abnormal blood vessel typically lies inside the liver. Such shunts are called intrahepatic Portosystemic shunts (IHPSS).
About This Research Project
Dr. Jan Rothuizen at the Utrecht University, Netherlands, is working with the Dutch BMDC to find a genetic marker for intrahepatic portosystemic shunts in BMDs so that breeders can determine whether dogs carry this defective gene.
Research at the University of Utrecht (Netherlands) has shown that intrahepatic shunts in Irish wolfhounds are caused by a genetic defect which has an autosomal recessive mode of inheritance. Further research on the condition in BMD's may make it possible to determine the mode of inheritance and eventually establish a genetic test for intrahepatic shunts in our breed, which will allow breeders to make sound breeding decisions to minimize the incidence of the condition.
What is Needed? (if you participate)
To isolate the gene causing this disease, the researchers need blood from affected dogs, their parents, and as many littermates as possible.
To participate please provide:
- 4 to 8 ml of blood in EDTA coated tubes (purple top) from the affected dog and as many relatives as possible sent via express mail;
- Veterinarian's report on the diagnosis of the shunt (blood test for ammonia, radiograph, surgery, etc);
- Pedigree of the affected dog;
Prior to sending your dog's sample and information, please notify in advance via e-mail Dr. Washabau (for N. American samples) or Dr, Rothuizen (for samples from outside N. America).