HP05 - Urine Isoprostane Concentrations in Dogs with Liver Disease

Abstract: Background – Isoprostanes are stable end products of lipid peroxidation that have been used as markers of oxidative stress in humans and dogs. It has previously been reported that a cohort of dogs with liver disease (inflammatory, metabolic, vascular, or neoplastic) had increased urine isoprostane concentrations compared to healthy control (HC) dogs. However, urine isoprostane concentrations have not been individually reported for different types of canine liver disease.

Hypothesis/Objectives – To assess oxidative stress in dogs with different types of liver disease.

Animals – Urine was collected from 21 HC dogs and from dogs with liver disease, including 25 with chronic hepatitis (CH), 7 with steroid hepatopathy (SH), and 8 with congenital portosystemic shunt (CPSS).

Methods – Prospective, observational study. Urinary 15-F_2t-isoprostane concentrations were measured by gas chromatography/negative ion chemical ionization mass spectrometry and normalized to urine 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.

Results – The median [range] urine 15-F_2t-isoprostane to creatinine ratios (ng/mg UCr) were 3.6 [2.2 - 12.4], 5.7 [2.4 - 11.3], 4.8 [2.4 - 8.6], and 12.5 [2.9 - 22.9] for HC dogs and dogs with CH, SH, or CPSS, respectively. CPSS dogs had significantly higher urine isoprostane concentrations compared to HC dogs (P = 0.0004).

Conclusions and clinical importance – These findings suggest that dogs with CPSS experience increased oxidative stress compared to HC dogs. If confirmed in a larger group of dogs, this may have therapeutic implications.