Liver shunts occur due to birth defects, according to PetEducation.com. When the fetal liver does not develop properly and cannot function, the blood supply passes around the liver rather than through it. The lack of blood passing through the liver prevents the liver from removing waste products.
Symptoms of liver shunts include but are not limited to lethargy, vomiting, poor growth rates, diarrhea and seizures, warns PetEducation.com. In severe cases, puppies with liver shunts may start exhibiting symptoms at only a few weeks of age, but in less severe cases, symptoms may not display for a year. However, all liver shunts are considered dangerous, with symptoms worsening even in mild cases as a dog gets bigger, due to the increased amount of metabolic waste being produced. Liver shunts severely shorten life expectancy in dogs.
Liver shunts are treated most successfully through surgery, states PetEducation.com. However, this is a complicated procedure that involves identifying and closing the abnormal blood vessels. It may sometimes be possible to control liver shunts through a low-protein diet supplemented with medication to reduce the production of toxic metabolic wastes. Generally speaking, the later a dog starts displaying symptoms, the more likely that liver shunts can be controlled through diet and medication.