Question from Ma Ma

Which are the symptoms of liver shunts in yorkies? My 4 years yorkie changed his behaviour in the last year, his afraid of a lot of things, is agressive with other dogs and looks quite tired all the time. Can be because of a health problem?? I thought is because we have a baby and we moved in a new house. Thank u

Answer from Shanika Winters (online vet)

Thank you for your question about liver shunts and the changes to your dog’s behaviour. It is possible that moving home and a new baby have had an effect on your dog’s behaviour but the symptoms you have listed are also found in cases of liver shunts.

What is a liver shunt?

Porto systemic shunt (PSS) commonly called a liver shunt is a condition where the blood vessels of the liver are abnormal; it is seen in dogs and cats. Miniature schnauzers and Yorkshire terriers are two breeds in which PSS seem to be found more often. The liver is a large organ found in the abdomen (belly) which processes and filters the products absorbed after food has been digested. The liver also produces vitamins, blood clotting factors and bile.

The blood full of nutrient and bacteria from the digestive system normally passes to the liver in the hepatic portal vein (large blood vessel) in cases of PSS the blood bypasses the liver via one or several vessels either inside (intrahepatic) or outside (extra hepatic) of the liver. The result of the PSS is that bacteria, unprocessed chemicals including ammonia stay in the blood and travel around the body leading to behavioural changes and poor body condition.

PSS can be congenital (present from birth) or acquired which occurs later in life. The symptoms are usually seen by 6 months of age and are accompanied by poor body condition and failure to gain weight.

What are the symptoms of PSS?

Polydipsia increased drinking

Polyuria increase urination
Anorexia decreased appetite
Depression quiet and uninterested in things
Lethargy less active than usual
Hepatic Encephalopathy (HE) a collection of neurological signs associated with liver disease
Ataxia lack of coordination when moving
Intermittent weakness weakness often within a few hours after eating a protein rich meal
Head pressing pushing head into corners of a wall or against furniture
Circling, Disorientation, Pacing, Altered behaviour, Seizures and Coma.

How is PSS diagnosed?

A detailed history of your pet’s behaviour, symptoms and general body condition will lead your vet to suspect liver disease and or PSS. Diagnostic tests start with routine blood tests, x-rays and ultrasound scans. If the test results point towards a liver problem the more specific liver function blood tests and or contrast imaging techniques can be used to detect the exact cause of the liver disease and where it is.

How is PSS treated?

PSS is treated medically in most cases but some cases can be treated surgically. Surgical treatment of PSS is when the shunt blood vessel is tied off so that blood is forced to pass via the liver again where it can perform its processing and filtering functions. Surgical treatment of PSS is usually carried out by a specialist vet after extensive diagnostic work up to locate the shunt vessels.

Medical management can help to keep the symptoms under control for a few years but does not cure the condition.

Medical treatment of PSS

Low protein diet, this is to reduce the amount of ammonia in the blood produced from the breakdown and digestion of protein. High levels of blood ammonia contribute to the signs of HE as listed. Lactulose can be given to reduce ammonia levels. Antibiotics are used to combat the increased levels of bacteria present in the blood and therefore increased risk of infections. Neutraceuticals are food additives that are thought to help in cases of liver disease these have not been proven to be beneficial and therefore only use after discussion with your vet.

I hope that this answer has helped you and that a diagnosis and treatment plan is put into place to help your dog soon.

Shanika Winter MRCVS (Online Vet)