Photo courtesy of Hot Bows.
This is the third in a series of occasional articles addressing medical problems of small breed dogs.
A liver shunt, more correctly called a portosystemic shunt, is not uncommon in toy breeds. In this disease, blood vessels, which should normally flow into the liver, bypass it. The liver cannot do its job, and ammonia from protein metabolism that is usually detoxified by the liver now builds up in the bloodstream.
This disease can be congenital or can develop later in life. Symptoms can be subtle and easy to miss in young dogs. Most symptoms are behavioral: lethargy, head pressing, walking in circles, behavior changes and, in severe cases, seizures. They tend to occur right after eating.
The liver is complex, and many other liver diseases can show the same symptoms. Blood samples give us a clue, and special blood samples can help us zero in on the liver. Ultrasound is very beneficial. Specialized tests include nuclear scans and injection of a dye into one of the veins and watching it flow past the liver.
An ultrasound of a normal liver, which is shown as the dark object in the center.
An ultrasound of a liver with a shunt. The arrow points to abnormal white blood vessels when measured by the Doppler. Photos courtesy of LBAH
The black vertical object is a normal blood vessel.
Treatment depends to a large degree on the severity of symptoms and location of the shunt. A special diet and medication can suffice in some cases. Surgery is highly effective and is used in most cases.
For more information, please visit this liver-shunt link on our website.