Canine Liver Shunt

The canine liver plays an important role in cleaning the blood and removing waste from the dog's system. A liver shunt is a condition that occurs if a blood vessel is sidetracked and bypasses the liver. The condition can be treated with drugs or surgery.

Liver Shunt in Dogs

Liver shunt in dogs is also known as portosystemic shunt or PSS. The condition manifests when a blood vessel that will bring blood from other vital organs bypasses the liver. The liver will not be able to filter this blood and the dog may have an increased amount of toxins, waste, sugar or bacteria in the blood. The condition will affect mostly the nervous system and the gastrointestinal system. Liver shunt can be an inherited condition or an acquired disease. Some dog breeds such as Yorkshire terriers, retrievers and shepherds are more likely to develop this condition.

Causes of Liver Shunt

Liver shunt in dogs is an idiopathic disease. The causes are not known. The disease will start as early as puppyhood, or when the dog is 2 or 3 years old.

Symptoms of Liver Shunt

The liver shunt will manifest through several symptoms, which will be due to the high toxicity of the blood:

  • Lethargy
  • Growth abnormalities, if the disease occurs at an early age
  • Confusion
  • Behavioral problems (irritability or aggression)
  • General state of weakness
  • Seizures
  • Vomiting and diarrhea
  • Lack of appetite or increased appetite, but no weight loss or gain
  • Kidney and bladder stones, especially if the disease occurs later in the dog's life

These symptoms may also point to hypoglycemia, trauma or hydrocephalus (water gathered in the brain).

Liver Shunt Diagnosis

The liver shunt can be diagnosed through a few blood tests, which will rule out other possible diseases that manifest through similar symptoms. The blood tests will reveal if the liver is functioning normally. The blood's toxicity levels will be increased. The blood tests that are essential in detecting a liver shunt include albumin, protein, urea as well as the bile acid concentration. X-rays and ultrasounds may also be performed to see the size of the liver and to detect the shunt. In dogs with liver shunt, the liver will be smaller than normal. A nuclear scan can also detect the presence of a shunt.

Treatment Options

Surgery is a treatment option, but it may not be necessary. The vet will assess the dog's condition and determine if surgery is needed. In some cases, surgery may be too risky and the vet may recommend medication treatment until surgery is possible. The first step is to change the dog's diet, so that the protein intake is lowered. Drugs that can be prescribed include lactulose, neomycin and metronidazole. These drugs are meant to absorb the toxins that are normally filtered by the liver. To prevent liver failure, surgery will be recommended. The shunt will be closed, but the dog should be monitored, as the liver shunt may become active again.