What is a portosystemic shunt in dogs? - briefly
A portosystemic shunt in dogs is an abnormal blood vessel that bypasses the liver, preventing proper detoxification of blood and leading to a buildup of toxins in the bloodstream.
What is a portosystemic shunt in dogs? - in detail
A portosystemic shunt (PSS) in dogs is a congenital or acquired vascular abnormality that allows blood to bypass the liver, diverting it directly from the portal vein into the systemic circulation. This bypass prevents the liver from properly detoxifying the blood, metabolizing nutrients, and regulating essential substances. In a healthy dog, the portal vein carries blood from the digestive organs to the liver, where it is processed before entering the general circulation. When a shunt is present, this critical filtration and metabolic function is compromised. Congenital shunts are more common and typically occur in young dogs, often small breeds such as Yorkshire Terriers, Maltese, and Miniature Schnauzers. Acquired shunts, on the other hand, develop later in life due to chronic liver disease or portal hypertension. Symptoms of a portosystemic shunt can vary but often include stunted growth, poor appetite, weight loss, vomiting, diarrhea, lethargy, behavioral changes, seizures, and in severe cases, hepatic encephalopathy. Diagnosis is typically confirmed through blood tests, imaging techniques such as ultrasound, CT scans, or MRI, and sometimes portal scintigraphy. Treatment options depend on the type and severity of the shunt. Surgical correction is often recommended for congenital shunts, involving the placement of a device to gradually restrict blood flow through the abnormal vessel, forcing it through the liver. Medical management, including a specialized diet, lactulose, and antibiotics, may be used for inoperable cases or to stabilize the dog before surgery. Early detection and intervention are crucial for improving the prognosis and quality of life for affected dogs. Without treatment, portosystemic shunts can lead to severe complications, including liver failure and neurological damage.