A remnant kidney surgery model in cats induces acute and chronic outcomes that mimic spontaneous chronic kidney disease

OBJECTIVE To report acute and chronic outcomes of cats with chronic kidney disease (CKD) induced by a remnant kidney model. ANIMALS 32 purpose-bred cats (n = 15 female, n = 17 male). PROCEDURES Cats underwent a 2-stage reduction in renal mass through partial arterial ligation of 1 kidney (day 28) and delayed contralateral nephrectomy (day 0), targeting an 11/12th functional nephrectomy. Acute (days -28 - 29) survival and renal function parameters were compared over time, and the latter were evaluated as predictors for acute mortality. Chronic (days 30 to >1,100) survival, renal function, and morphology were described. RESULTS Acutely, renal function deteriorated in all cats (mean +/- SD baseline and day 28 serum creatinine mean concentration, 1.13 +/- 0.23 mg/dL and 3.03 +/- 1.20 mg/dL, respectively; P <.001; and GFR, 3.22 mL/min/kg +/- 0.12 and 1.21 mL/min/kg +/- 0.08, respectively; P <.001). Seven (22%) cats were euthanized after because of clinical signs of uremia after contralateral nephrectomy. Prenephrectomy renal function tests were not significant indicators for survival during this acute phase. Twenty-five cats entered the chronic phase. Ten cats were euthanized at a median of 163 days from nephrectomy because of progressive renal dysfunction. Median survival times were significantly different when stratified by acute kidney injury grade at day 29. Cats in the chronic phase had clinical courses similar to cats with naturally occurring CKD, and most (13/15) were in CKD stage 2.