Chronic nephritis is common in middle-aged and elderly cats, with a relatively slow course, but the causes are roughly the same as acute nephritis; gingivitis, stomatitis, bacterial endocarditis, and other factors may cause it.

　　Affected cats show decreased appetite, increased water intake and urination, weight loss, and severe bad breath; the true cause must be identified and treated, along with nutritional supplementation, so the cat can rest peacefully and gradually recover. (Source：PetsZone)