The urinary lipid profile in cats with idiopathic cystitis

Although feline idiopathic cystitis (FIC) distresses of many cats, its pathogenesis is unknown and the diagnosis is challenging. Polyunsaturated fatty acids (PUFAs) are metabolized into various lipid mediators. Lipid mediators such as prostaglandins (PGs) modulate inflammation and many of them are excreted into the urine. Thus, the investigation of the urinary lipid profile may reveal pathogenesis and help diagnosis of FIC. We collected urine samples from five FIC cats by spontaneous urination and analyzed 158 types of lipid mediators in urines using liquid chromatography-mass spectrometry. The urinary levels of PUFAs were higher in FIC compared to those of the healthy group. The excretions of a major inflammatory mediator, PGD₂, were less in FIC. Other well-known inflammatory mediators such as PGE₂, PGI₂, and their metabolites did not show a difference. In contrast, the levels of PGF_2α and its 2 metabolites and PGF_3α were higher in FIC. These results may provide new insights into the future management of cat FIC.