Abstract
Case series summaryA retrospective, single-center case series describes five cats with primary portal vein hypoplasia (PVH). This case series outlines clinical signs, diagnostics, treatments and prognosis in cats diagnosed with primary PVH based on histopathology. Pathology records from cats that underwent liver biopsies were retrospectively searched to identify cats with histologic features of portal vein hypoperfusion. Patients with concurrent hepatic conditions such as portosystemic shunts, portal vein obstruction, arteriovenous fistulas and other hepatic conditions that complicate vasculature were excluded, leaving five cases for inclusion. In this case series, 3/5 cats were asymptomatic, with abnormalities detected on biochemistry or abdominal ultrasound, one cat presented with lethargy and one cat presented with gastrointestinal signs associated with a foreign body. Of the five cats in this series, four underwent treatment with follow-up biochemistry profiles. One cat in this study was a well-controlled diabetic and hyperthyroid, while one cat was newly diagnosed with hyperthyroidism after biopsies, which complicated liver enzyme interpretation. Treatment protocols were variable and encompassed management of concurrent metabolic disorders, use of hepatoprotective medications, hepatic encephalopathy therapy, antimicrobial treatment, copper chelation and immunosuppressive therapy. A larger case series or a prospective study is necessary to establish the optimal treatment plan, as there were no established standards for managing this condition for this cohort. Four cats with confirmed follow-up had an average survival time of 878.5 days after diagnosis, indicating a favorable prognosis.Relevance and novel informationPVH is a stereotypical microscopic finding in liver portal tracts, most often linked to portosystemic shunts. It can occur with any condition that reduces portal blood flow. In the absence of a shunt, arteriovenous fistula or portal vein obstruction, it is termed primary portal vein hypoplasia, which is poorly characterized in cats.