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Treatment
Medical
Fluids and Electrolytes
This corrects the dehydration that occurs with a poor appetite and supplies needed sodium, potassium, and chloride. This fluid is usually given intravenously (IV) at first. Pets that are severely ill from PSS should not be given anything orally initially.
Cleansing Enemas
Enema's will decrease the bacterial count of the intestines, leading to less ammonia absorption.
Lactulose
Lactulose works in the large intestine to minimize the production of ammonia by bacteria. It does this by changing the pH and converting ammonia to a form that is not readily absorbed into the bloodstream. It also stimulates normal colon bacteria to absorb ammonia, which is then passed in the feces. Finally, it stimulates the intestines so that ammonia passes through faster, which means there is less time for absorption.
Antibiotics
These drugs are also administered, especially if mental depression is present. They minimize the bacteria count in the colon, thus reducing the amount of ammonia that is absorbed from the intestines into the bloodstream. They work well with lactulose to decrease the ammonia level.
Dietary Modification
A diet that is restricted in protein may be beneficial because less ammonia is produced as a by-product of metabolism. This protein needs to be of high biological value, such as eggs and dairy products. Meat based proteins should be avoided since they can increase the chance of HE. Most of the caloric needs of a pet with PSS should be supplied with carbohydrates. Higher fiber diets might also be helpful, as long as the dog or cat is not undernourished. They can act to minimize ammonia production and absorption in a manner that is similar to lactulose.
Hill Prescription Diet L/DŽ is very helpful in liver disease. It contains added amounts of nutrients that a diseased liver needs. It also has restricted amounts of nutrients that can make the condition worse. For example, sodium (Na) is limited to minimize fluid buildup in the abdomen (ascites).
Surgical
For many PSS cases surgery is the treatment of choice. The abnormal vessel that is shunting blood around the liver is identified and closed (ligated) to minimize blood flowing through it. When the abnormal blood vessel is ligated blood will now flow through the liver instead of around it. This is readily accomplished for solitary extrahepatic shunts. Intrahepatic shunts can be more difficult to identify and ligate. Post surgical monitoring is important. If the pressure within the liver becomes too high due to the increased blood flow through the liver then the ligation on the shunting vessel(s) must be reduced or removed.
In some cases medical management must also be utilized to affect a cure. The final outcome of treatment depends on what age the PSS started, how long it has been present, and whether it is intrahepatic (worse prognosis) or extrahepatic in nature.
Long Term Monitoring
Pets on long term medical care need to be monitored carefully. Body weight, albumin, and total protein are watched to ensure adequate protein in the diet. Initially, these tests should be performed monthly, then every 3 months. In addition to the above tests, bile acids are monitored monthly, then every three months to assess the vitality of the liver. Blood ammonia levels are monitored monthly to assess effectiveness of treatment. When stable, ammonia levels can be monitored every 3 months.
Prognosis
Many pets with isolated extrahepatic shunts return to a normal life after surgery. There is no guarantee that surgery will correct the problem, especially those pets that develop the disease very early in life. Some of them will need medical management simultaneously. The prognosis for pets that are treated only medically varies. Cats do not do as well as dogs when surgery is attempted. |