Research overview: tubulointerstitial pathology in feline CKD

The most common histopathologic finding in feline CKD is chronic tubulointerstitial nephritis with fibrosis, a pattern of scarring and inflammation that progressively replaces functional kidney tissue. Unlike some species in which glomerular disease predominates, cats most often show this interstitial pattern, whose ultimate triggers remain incompletely understood and likely multifactorial, including ischemia, prior injury, and aging. This overview synthesizes the pathology literature rather than one citation, describing the characteristic lesions, why fibrosis is the common endpoint of diverse insults, and how understanding the underlying tissue changes motivates research into antifibrotic and renoprotective therapies. It matters because identifying the drivers of progressive scarring is central to the search for treatments that could slow or halt this widespread feline disease.