has been reported to occur in 19 to 20% of cats with CKD and was moderate to severe in more than half of the cases in one study (DiBartola et al,1987; Elliott and Barber, 1998). Conversely, hyperkalemia was observed in 9 to 13% of these cats.Hyperkalemia was observed in oliguric and polyuric kidney disease and was most common (22%) in cats with endstage CKD.