Urinary 15-F(2t)-Isoprostane Concentrations in Dogs with Liver Disease

SIMPLE SUMMARY: Similar to humans, dogs are affected by a variety of liver diseases with various causes and presentations. Recently, growing interest has focused on measuring markers of oxidative stress in patients with liver disease; however, no study to date has compared markers of oxidative stress between dogs with different liver diseases. This study aimed to evaluate markers of oxidative stress in dogs with different types of liver disease by measuring a compound known as 15-F(2t)-isoprostane in their urine. Among dogs with one of three different types of liver diseases, only those with a congenital portosystemic shunt (CPSS) had a significant increase in this oxidative stress marker when compared with a group of healthy control dogs. ABSTRACT: Isoprostanes are stable end products of lipid peroxidation that can be used as markers of oxidative stress. It was previously reported that a cohort of dogs with various liver diseases had increased urinary isoprostane concentrations compared to healthy control (HC) dogs. The aim of this study was to measure and report urinary isoprostane concentrations in dogs with different types of liver diseases. Urine was collected from 21 HC dogs and from 40 dogs with liver disease, including 25 with chronic hepatitis (CH), 7 with steroid hepatopathy (SH), and 8 with a congenital portosystemic shunt (CPSS). In this prospective, observational study, urinary 15-F(2t)-isoprostane (F(2)-IsoP) concentrations were measured by liquid chromatography/mass spectrometry and normalized to urinary creatinine concentrations. Concentrations were compared between groups using a Kruskal–Wallis test followed by Dunn’s multiple comparisons tests. Significance was set at p < 0.05. The median (range) urinary F(2)-IsoP to creatinine ratios (ng/mg UCr) were 3.6 (2.2–12.4) for HC dogs, 5.7 (2.4–11.3) for dogs with CH, 4.8 (2.4–8.6) for dogs with SH, and 12.5 (2.9–22.9) for dogs with CPSS. CPSS dogs had significantly higher urinary F(2)-IsoP concentrations than HC dogs (p = 0.004), suggesting increased oxidative stress among this cohort.