Understanding congenital portosystemic shunts in dogs — a liver disease requiring surgical correction for welfare.
Portosystemic shunts cause progressive welfare impairment through hepatic insufficiency and recurrent encephalopathy episodes. Affected puppies are often smaller than litter-mates and show neurological signs — disorientation, head pressing, circling, seizures — typically occurring after meals when ammonia load from gut protein digestion peaks. The encephalopathic episodes are frightening — puppies appear profoundly confused, may vocalise, and may injure themselves during seizures.
Without treatment, neurological signs progress and quality of life deteriorates. The liver fails to develop normally without adequate portal blood flow, causing permanent hepatic insufficiency. Dogs managed medically alone typically deteriorate over months to years.
Surgical shunt attenuation (using ameroid constrictors, cellophane banding, or intravascular coils) provides the best long-term welfare outcome. The liver receives normal portal blood flow, develops normally, and hepatic function improves progressively after surgery. Most dogs with successfully treated PSS enjoy normal quality of life. Surgery risk is real but the welfare benefit justifies it for most cases.