If your cat suffers from kidney disease it may benefit from a special diet in the long term kidney disease in cats is generally chronic in cases of damage to the kidney the ability to filter toxins is disturbed loss of appetite is the result renal disease also has a negative effect on the urinary tract purina veterinary diets feline nf renal function has a lower phosphorus content as phosphorus can make kidney disease worse lower protein levels help to minimise protein metabolites and