The present invention provides a method of diagnosing the existence of a kidney disorder in a feline comprising measuring the level of expression of one or more biomarkers selected from the group consisting of lumican； collagen alpha 1 (111) chain, variant 12； decorin； secreted frizzled-related protein 2； retinol binding protein 5； MMP-2； MMP-7； and MMP-19, in a biological sample from the feline, wherein differences in expression of the one or more biomarkers in the sample relative to a control value for expression in a sample from a normal animal indicate the existence of a kidney disorder； a method of treating a feline so diagnosed； and compositions, reagents and kits for carrying out the specified methods.
