Acute Kidney Injury

Acute kidney injury describes a situation in which the kidneys suddenly lose much of their ability to filter waste from the blood. This can happen over hours or days, rather than the slow decline seen in chronic kidney disease. The kidneys may recover function if the underlying cause is identified and addressed, though the degree of recovery varies. Owners often notice a sudden change in how much their pet is drinking or urinating—sometimes much more than usual, sometimes very little. Appetite may drop sharply, and vomiting or listlessness can appear within a short window. The change tends to be abrupt enough that many owners can identify when things shifted. This page explores what signs may appear in the early stages, what mechanisms inside the kidney can lead to this kind of injury, how the condition is investigated through blood tests and imaging, and what approaches exist depending on the cause and severity. The focus is on understanding what acute kidney injury looks like and how it tends to unfold.