Objectives This study aimed to evaluate the prevalence of urolithiasis in dogs with primary portal vein hypoplasia and to compare clinicopathological changes and clinical signs between dogs with and without uroliths. Materials and Methods The clinical records of 15 UK referral hospitals were searched for dogs diagnosed with primary portal vein hypoplasia between 2010 and 2023. Dogs lacking a histopathological diagnosis and those without comprehensive diagnostic imaging to exclude congenital extrahepatic or intrahepatic portosystemic shunts were excluded. Medical records were reviewed for clinical signs, biochemical parameters, urinalysis findings and the presence or absence of urolithiasis. Results Fourteen dogs with a definitive diagnosis of primary portal vein hypoplasia were documented, of which four (28.5%) had urolithiasis. All dogs with urolithiasis had crystalluria. One of the four dogs (25%) had bilirubin crystals, while the three other dogs (75%) with urolithiasis had ammonium biurate crystalluria, and two (50%) exhibited lower urinary tract signs. The median age was 15 months (range 3 to 38) and 39 months (range 6 to 104) in dogs with or without urolithiasis, respectively. The median duration of clinical signs was 71 days (range 14 to 150) in dogs with urolithiasis and 135 days (range 3 to 365) in those without. Acquired extrahepatic portosystemic shunts were documented in 2/4 (50%) dogs with urolithiasis and 1/10 (10%) of dogs without. Clinical Significance Dogs with primary portal vein hypoplasia were at risk of developing uroliths, including both lower and upper urinary tract stones, and often exhibited associated clinical signs. These findings highlight the importance of performing urinalysis and diagnostic imaging in the evaluation of dogs with this condition.
Travail et al. (2026) studied this question.