Maintenance phase
A phase of acute renal failure following initiation during which oliguria persists. Whether an ARF patient is oliguric or polyuric reflects the severity of insult which caused ARF. The majority of ARF dogs and cats become oliguric although some ARF patients are never oliguric. In those patients which can repair the renal damage, the oliguric phase lasts 1-2 weeks. Many animals die or are euthanized during the oliguric phase because of the poor prognosis. The most life-threatening consequences of the oliguric phase include hyperkalemia and overzealous fluid therapy resulting in overhydration.