Portosystemic Shunt

What is Portosystemic Shunt?

Portosystemic Shunt (PSS) is a condition where there is a bypass between the blood supplies to the liver allowing blood to avoid the liver during circulation.

How does my dog get Portosystemic Shunt?

This communication between the portal and systemic venous circulation is usually congenital although may be acquired during end stage liver disease. The communication may be within the liver itself (intrahepatic) or outside of the liver (extrahepatic). In congenital situations, it is usually single in nature. In acquired PSS, due to increased pressure in the portal vessels, PSS are usually multiple.

How do I know if my dog has Portosystemic Shunt?

The signs and symptoms are usually first noticed by six months of age and rarely beyond 2 years of age. The signs or symptoms that you might see are do to the failure of the liver to be able to remove the toxins from the blood. Gastrointestinal signs such as vomiting or diarrhea are common. Later on, the development of bladder stones and neurological signs are common. The blood flow changes lead to a small liver size. Your veterinarian is the only one that can definitively confirm PSS. Diagnosis requires a series of tests including radiographs, blood samples, special blood tests, and frequently ultrasound. Signs may come and go with symptomatic treatment of the signs of anorexia, vomiting, diarrhea, or lethargy. Other signs noted: stunted growth, increased water consumption and urination, blood in the urine (if stones present), disorientation, seizures, behavior changes, and many others. In cats, hyper-salivation has been reported.

What can I do about Portosystemic Shunt?

Once the diagnosis is confirmed and the significance of the shunt is identified, there are a just a few options. Without surgery, there is a poor long term prognosis. Surgery to tie off (ligate) the shunt is treatment of choice but comes with its own set of risks. Diets and snacks high in protein much be avoided. Medical management may prolong life for months or years in dogs but is less effective in cats. After surgery and recovery, there may be no need for significant long term life style changes.

Is there anything I can do to prevent my dog from getting Portosystemic Shunt?

Very careful breed selection will help to avoid many cases. In older dogs, anything to minimize work that the liver has to do and thus decrease the likelihood of development of end stage liver failure.

Are there certain breeds that get Portosystemic Shunt more often?

Greatest frequency in the Miniature schnauzers and Yorkshire terriers, but also seen in Cocker Spaniel, Australian Cattle Dog, Cairn terrier, Dachshund, Irish Wolfhound, Maltese.