Portosystemic Shunts in Dogs: A Plain English Guide (2023)

Portosystemic shunts (PSS) in dogs are a complex medical condition that can be daunting for pet owners to grasp. This condition involves abnormal blood flow, bypassing the liver. Normally, blood from the intestines, spleen, and pancreas travels through the liver where toxins are removed before it enters general circulation.

In dogs with PSS, this blood is diverted, leading to a buildup of toxins in the bloodstream.

Causes and Types

Portosystemic Shunts in Dogs vet

Type of PSS Causes Age of Onset Associated Factors
Congenital Present at birth Typically in younger dogs Genetic factors
Acquired Develop due to liver diseases (e.g., cirrhosis) Can occur at any age Liver diseases, increased portal vein pressure

Identifying the Symptoms

Symptoms of PSS can vary but often include poor growth in puppies, neurological issues due to toxin buildup (like disorientation or seizures), gastrointestinal problems, and urinary issues.

Early detection is crucial, as the buildup of toxins can have long-term effects on a dog’s health.

Diagnosis and Treatment of PSS

Treatment of PSS

Diagnosing PSS involves a combination of blood tests, imaging, and sometimes exploratory surgery. Blood tests can reveal elevated liver enzymes and abnormal ammonia levels.

Imaging techniques like ultrasounds or CT scans help locate the shunt. In some cases, a contrast dye may be used to highlight the abnormal blood flow.

Surgical Interventions

The gold standard for treating PSS is surgical intervention, where the abnormal vessel is closed off, forcing blood back through the liver. This procedure, however, can be complex and is usually performed by veterinary specialists.

Post-surgery, dogs are closely monitored, as there is a risk of portal hypertension (increased blood pressure in the portal vein).

Non-Surgical Management

In cases where surgery isn’t an option, medical management focuses on reducing toxin buildup. This includes a special diet low in protein, medications to decrease ammonia production, and laxatives to reduce toxin absorption in the intestines.

Long-term prognosis in these cases depends on the dog’s response to medical management.

Diet and Lifestyle Adjustments

Post-diagnosis, dietary changes are vital. A diet low in protein helps reduce the amount of ammonia produced, which is crucial for dogs that cannot undergo surgery. Regular monitoring and adjustments based on the dog’s condition are necessary.

Monitoring and Long-term Care

Regular veterinary check-ups are essential to monitor the dog’s health and adjust treatment as needed. Blood tests are typically performed periodically to ensure that liver function is maintained and to adjust medications.

Prognosis and Life Expectancy


The prognosis for dogs with portosystemic shunts largely depends on several factors, including the type of shunt, the dog’s overall health, and whether the condition is congenital or acquired.

Dogs with congenital shunts that receive timely surgical treatment often have a good prognosis, with many leading normal lives post-surgery. For acquired shunts, the underlying liver disease plays a significant role in the dog’s prognosis.

Life Expectancy Post-Treatment

Life expectancy for dogs post-treatment can vary. Dogs that undergo successful surgery for congenital shunts often have a normal lifespan. However, for those with acquired shunts or those managed medically, life expectancy may be reduced, depending on the severity of the liver disease and the effectiveness of the management plan.

Importance of Early Detection

Early detection and intervention are crucial in improving the prognosis. Dogs that are diagnosed and treated early, especially with surgical intervention, typically have a better outcome and quality of life. Regular veterinary check-ups and being aware of the signs and symptoms of PSS can aid in early detection.

Genetic Testing and Breeding Considerations

Genetic Testing

Genetic testing plays a pivotal role in identifying dogs that may be at risk of congenital portosystemic shunts. While the exact genetic markers are still being researched, genetic testing can help identify breeds that are predisposed to this condition and can be a valuable tool for breeders.

For breeds known to be predisposed to PSS, responsible breeding practices are essential. Breeding dogs should be screened for PSS, and those with a history of the condition should be excluded from breeding programs. This approach helps reduce the incidence of congenital shunts in future generations.

Education is key in managing the incidence of PSS. Breeders should be informed about the risks and the importance of genetic screening. Similarly, prospective dog owners should be aware of the condition, especially if considering a breed with a higher predisposition to PSS.


Can a dog with a portosystemic shunt have a normal exercise routine?

Dogs with portosystemic shunts often require a modified exercise routine. While mild to moderate exercise can be beneficial, strenuous activities should be avoided, especially in dogs that have not undergone surgery.

It’s important to consult with a veterinarian to determine an appropriate exercise plan based on the dog’s specific condition and overall health.

Are there any particular breeds more susceptible to portosystemic shunts?

Yes, some breeds are more predisposed to congenital portosystemic shunts. These include Yorkshire Terriers, Maltese, and Irish Wolfhounds, among others. However, PSS can occur in any breed, and genetic factors are still being researched to better understand breed-specific predispositions.

How long does it take for a dog to recover from surgery for a portosystemic shunt?

Recovery time varies depending on the individual dog and the complexity of the surgery. Typically, it takes about 2 to 6 weeks for a dog to recover fully from PSS surgery. During this time, close monitoring and follow-up visits with the veterinarian are essential to ensure a smooth recovery.

Can a dog with a portosystemic shunt have a normal diet after surgery?

Post-surgery, the dietary needs may change. Initially, a low-protein diet is often recommended to reduce the workload on the liver. However, as the dog recovers and liver function improves, the diet can often be gradually returned to a more normal composition.

This should always be done under the guidance of a veterinarian.

Is there a way to prevent portosystemic shunts in dogs?

Currently, there’s no sure way to prevent congenital portosystemic shunts, as the condition is often hereditary. However, responsible breeding practices, including genetic screening, can help reduce the risk of PSS in predisposed breeds.

For acquired shunts, maintaining overall liver health and preventing liver diseases can be beneficial.

Are there any long-term medications required for a dog with PSS?

For dogs that are not surgical candidates or those with residual issues post-surgery, long-term medications may be required. These can include medications to reduce ammonia production, supplements to support liver function, and possibly antibiotics to manage any associated bacterial overgrowth in the intestines.

The specific medication regimen should be tailored to each individual dog’s needs.


In essence, portosystemic shunts in dogs might sound complicated, but they’re a part of some dogs’ lives that we can manage with care and knowledge. It’s about spotting the signs early, working with a good vet, and giving our furry friends the right treatment and love.

Whether it’s through surgery or special diets and meds, there’s a lot we can do to help our dogs lead happy, comfortable lives. With a bit of understanding and a lot of heart, we can make a big difference in the lives of our four-legged pals who are facing this challenge.