Clinical relevance of radiographic linear branching mineral opacities in the canine liver.

Abstract

Objectives: Mineral opacities within the liver or biliary system are usually considered incidental but have been reported in one dog to be associated with choledocoliths, and biliary tree mineralisation is seen occasionally in dogs with bile duct carcinoma. The purpose of this study was to assess the prevalence, clinical significance and breed distribution of linear branching mineralisation superimposed on the hepatic silhouette from radiographs of dogs from one referral institution. The hypothesis was that linear branching mineralisation is an incidental finding in dogs. Methods: Medical records and images of dogs with branching mineralisation seen on radiographs +/- ultrasound in the liver were reviewed retrospectively to characterize and assess their clinical significance. Results: Only 17 cases were found over 30 years. Out of those, 41% were Cavalier King Charles Spaniels (CKCS), and only 23% of all dogs were diagnosed with a disease known to be affecting the hepatobiliary system primarily or secondarily. The mineralisation had a predominantly ventral distribution in all cases. Five dogs had repeat radiographs, and no change in the pattern of mineralisation was detected in four dogs and only one dog developed the pattern 6 years after being diagnosed with cholangiohepatitis. Serum calcium concentrations were normal in all patients. Liver enzymes were only markedly elevated in the dog which was diagnosed with cholangiohepatitis. Histology performed on 3 patients did not show convincing evidence of primary liver disease or any pathology to cause this pattern of mineralisation. Impact: This study suggests that branching mineralisation in the liver parenchyma is a rare finding in dogs with little to no clinical significance and that Cavalier King Charles Spaniels may be predisposed. Therefore, biopsy of the liver of these dogs where there is no clinical or clinicopathological evidence of liver disease might be avoided in these cases. Key words: radiography, biliary, mineralisation, dog.