Portosystemic Shunt Ligation


A portosystemic shunt is an abnormal vessel that allows venous blood from the abdominal organs to return directly into the systemic circulation rather than through the portal vein into the liver. Ligation of the shunt involves an abdominal surgery to place a ligature or an ameroid constrictor around the shunt vessel in order to redirect blood back through the liver. An ameroid constrictor placement is the preferred method in most cases since it slowly occludes the vessel over a period of several weeks, thus reducing the incidence of complications.


Surgical treatment is advised for animals with a congenital portosystemic shunt that are presented with clinical signs related to the shunt, such as neurologic abnormalities, lethargy, poor growth, weight loss, vomiting and/or diarrhea, and urinary tract dysfunctions. Animals with multiple acquired shunts are usually not good candidates for shunt ligations.

Postoperative Care

Give any prescribed medication as directed, and do not give human drugs without first consulting with a veterinarian. If vomiting is consistently observed following medication, please contact our surgical staff.

A low protein diet should be continued following surgery. If the shunt was completely occluded or if an ameroid constrictor was used, then a normal diet should be possible after 2 to 3 months. If the shunt could only be partially occluded, then the low protein diet should be continued indefinitely.

Limit exercise to short leash walks until the sutures are removed, and do not allow running, jumping, or playing with other pets for three weeks.

Observe your pet for problems, and contact us if you notice any of the following:

  • Continued or worsening neurologic deficits or seizures
  • Prolonged listlessness or anorexia
  • Abdominal distension
  • Sudden collapse
  • Persistent vomiting

Please schedule an appointment for suture removal 7 to 10 days after surgery. Please contact us immediately if any of the above problems are noted. Another examination is recommended approximately 6 weeks postoperatively to repeat blood work (bile acids). Your regular veterinarian can perform this follow-up visit.


Left untreated, portosystemic shunts are almost invariably fatal within months to years. Although shunt ligation is a relatively high-risk surgical and anesthetic procedure, most dogs (approximately 85%) will recover from surgery and be cured. The liver can regenerate and resume normal function once the blood has been redirected.

Your pet’s recovery and well-being are our primary concerns, so please do not hesitate to call and speak with a surgical technician or surgeon if there are any questions regarding your pet’s recovery.