Hepatic parenchymal hypoattenuation in dogs with diabetes mellitus on computed tomography consistent with hepatic steatosis

Hypoattenuation of the liver, consistent with hepatic steatosis or lipidosis, has been reported in veterinary patients. In people, measuring CT hepatic attenuation is diagnostic for hepatic steatosis, and hypoattenuation of the liver is defined as absolute if less than 40 HU or relative if the liver is 10 HU less than the spleen. The purpose of this study is to describe hepatic parenchymal attenuation in dogs with diabetes mellitus with or without diabetic ketosis (DK) or diabetic ketoacidosis (DKA), using the above categorization for absolute and relative hypoattenuation, as with humans. We hypothesized dogs with DK or DKA were more likely to have hypoattenuating livers. Twenty-seven diabetic dogs were included; fifteen were categorized in Group 1 as without DK or DKA, six in Group 2 as DK, and six in Group 3 as DKA. In Group 3, four of six dogs had absolute and relative hypoattenuating livers. Three of these were visually hypoattenuating to the vasculature, with one having negative attenuation and a histopathologic diagnosis of severe hepatic lipidosis. In Group 2, four of six dogs had relative hypoattenuating livers. In Group 1, only one of 15 dogs had a relatively hypoattenuating liver. Groups 2 and 3 had significantly lower absolute liver attenuation than Group 1. Presumed hepatic steatosis was present on CT and was more common with DK or DKA. These findings may help provide hepatic sampling recommendations and alter patient prognosis. Further research is needed to establish absolute and relative liver attenuation in dogs with correlation to histopathology and patient outcome.